Google Adwords API: INVALID_TOKEN_HEADER when using new API and correct Developer Token (i believe)

I am having an issue with Google Adwords API and can't seem to get it to work.

I have taken the following steps:

• Installed composer
• Installed Google Adwords API
• Created a Developer Token
• Created Oauth2
• Created a Refresh Token
• Updated all of the above inside of adsapi_php which is in the root
• I also have Basic access to the API

<?php namespace Google\AdsApi\Examples\AdWords\v201809\Reporting; require __DIR__ . '/vendor/autoload.php'; use Google\AdsApi\AdWords\AdWordsServices; use Google\AdsApi\AdWords\AdWordsSession; use Google\AdsApi\AdWords\AdWordsSessionBuilder; use Google\AdsApi\AdWords\v201809\cm\ReportDefinitionReportType; use Google\AdsApi\AdWords\v201809\cm\ReportDefinitionService; use Google\AdsApi\Common\OAuth2TokenBuilder; /**  * This example gets the fields available in a campaign report.  */ class GetReportFields{     const PAGE_LIMIT = 500;     public static function runExample(AdWordsServices $adWordsServices,         AdWordsSession $session){         $reportDefinitionService = $adWordsServices->get($session, ReportDefinitionService::class);         // The type of the report to get fields for.         $reportType = ReportDefinitionReportType::CAMPAIGN_PERFORMANCE_REPORT;         // Get report fields of the report type.         $reportDefinitionFields = $reportDefinitionService->getReportFields($reportType);         printf(             "The report type '%s' contains the following fields:\n",             $reportType         );         foreach ($reportDefinitionFields as $reportDefinitionField) {             printf(                 '  %s (%s)',                 $reportDefinitionField->getFieldName(),                 $reportDefinitionField->getFieldType()             );             if ($reportDefinitionField->getEnumValues() !== null) {                 printf(                     ' := [%s]',                     implode(', ', $reportDefinitionField->getEnumValues())                 );             }             print "\n";         }     }     public static function main(){         // Generate a refreshable OAuth2 credential for authentication.         $oAuth2Credential = (new OAuth2TokenBuilder())->fromFile()->build();         // Construct an API session configured from a properties file and the         // OAuth2 credentials above.         $session = (new AdWordsSessionBuilder())->fromFile()->withOAuth2Credential($oAuth2Credential)->build();         self::runExample(new AdWordsServices(), $session);     } } GetReportFields::main(); ?> 

But I am receiving the following error:

Fatal error: Uncaught Google\AdsApi\AdWords\v201809\cm\ApiException: [QuotaCheckError.INVALID_TOKEN_HEADER @ ; trigger:'New developers must use the Google Ads API: https://developers.google.com/google-ads/api/docs/start'] in C:\xampp\htdocs\vendor\googleads\googleads-php-lib\src\Google\AdsApi\Common\Util\Reflection.php:43 Stack trace:  #0 C:\xampp\htdocs\vendor\googleads\googleads-php-lib\src\Google\AdsApi\Common\Util\Reflection.php(43): ReflectionClass->newInstanceArgs(Array) #1 C:\xampp\htdocs\vendor\googleads\googleads-php-lib\src\Google\AdsApi\Common\AdsSoapClient.php(203): Google\AdsApi\Common\Util\Reflection->createInstance('Google\\AdsApi\\A...', Array) #2 C:\xampp\htdocs\vendor\googleads\googleads-php-lib\src\Google\AdsApi\Common\AdsSoapClient.php(165): Google\AdsApi\Common\AdsSoapClient->parseApiExceptionFromSoapFault(Object(SoapFault)) #3 C:\xampp\htdocs\vendor\googleads\googleads-php-lib\src\Google\AdsApi\AdWords\v201809\cm\ReportDefinitionService.php(89): Google\AdsApi\Common\AdsSoapClient->__soapCall('getReportFields', Array) #4 C:\xampp\htdocs\adwords.php(31): Google\AdsApi\AdWords\v201809\cm\ReportDefinitionService->getReportFields('CAMPAIGN_PERFOR...') #5 C:\xampp\htdocs\adwords.php(61): Google\AdsApi\Examples\AdWords\v201809\Reporting\GetReportFields::runExample(Object(Google\AdsApi\AdWords\AdWordsServices), Object(Google\AdsApi\AdWords\AdWordsSession)) #6 C:\xampp\htdocs\adwords.php(65): Google\AdsApi\Examples\AdWords\v201809\Reporting\GetReportFields::main() #7 {main} thrown in C:\xampp\htdocs\vendor\googleads\googleads-php-lib\src\Google\AdsApi\Common\Util\Reflection.php on line 43 

Now I am certain the credentials are all correct. Inside of https://developers.google.com/adwords/api/docs/common-errors#QuotaCheckError.INVALID_TOKEN_HEADER it states there are only two potential issues:

• The developer token is not set on the request or it contains a typo.
• The namespace of the headers in the request is not correct.

So the only issue could be the namespace of the headers but I do not understand how to: "Ensure that the headers of the request are in the namespace https://adwords.google.com/api/adwords/cm/{version}, where {version} is replaced with the version of the API being used."

Where do I find the version to confirm if this is the issue or if it is somehow that I am using the wrong API which a new developer tokens are unable to be used on: https://developers.google.com/adwords/api/docs/guides/signup? Although I did follow the new documentation to the letter...

Or is it that it is unable to find the adsapi_php? Thus it is always wrong? Any advice for finding out where the issues lies? I have been trying to troubleshoot this since 10am this morning.

If it helps here is my composer.json:

{     "name": "phpmyadmin/phpmyadmin",     "type": "project",     "description": "A web interface for MySQL and MariaDB",     "keywords": ["phpmyadmin","mysql","web"],     "homepage": "https://www.phpmyadmin.net/",     "support": {         "forum": "https://www.phpmyadmin.net/support/",         "issues": "https://github.com/phpmyadmin/phpmyadmin/issues",         "wiki": "https://wiki.phpmyadmin.net/",         "docs": "https://docs.phpmyadmin.net/",         "source": "https://github.com/phpmyadmin/phpmyadmin"     },     "license": "GPL-2.0-only",     "authors": [         {             "name": "The phpMyAdmin Team",             "email": "developers@phpmyadmin.net",             "homepage": "https://www.phpmyadmin.net/team/"         }     ],     "non-feature-branches": ["RELEASE_.*"],     "autoload": {         "psr-4": {             "PhpMyAdmin\\": "libraries/classes"         }     },     "autoload-dev": {         "psr-4": {             "PhpMyAdmin\\Tests\\": "test/classes",             "PhpMyAdmin\\Tests\\Selenium\\": "test/selenium/"         }     },     "repositories": [         {             "type": "composer",             "url": "https://www.phpmyadmin.net"         }     ],     "require": {         "php": "^7.1.3 || ^8.0",         "ext-hash": "*",         "ext-iconv": "*",         "ext-json": "*",         "ext-mysqli": "*",         "ext-pcre": "*",         "ext-xml": "*",         "firebase/php-jwt": "^3.0",         "google/apiclient": "^2.0",         "google/gax": "^1.7",         "google/recaptcha": "^1.1",         "googleads/google-ads-php": "^10.1",         "googleads/googleads-php-lib": "^53.0",         "guzzlehttp/guzzle": "^7.0",         "nikic/fast-route": "^1.3",         "phpmyadmin/motranslator": "^5.0",         "phpmyadmin/shapefile": "^2.0",         "phpmyadmin/sql-parser": "^5.0",         "phpmyadmin/twig-i18n-extension": "^3.0",         "phpseclib/phpseclib": "^2.0",         "react/http": "^1.4",         "spatie/crawler": "^7.0",         "symfony/config": "^4.4.9",         "symfony/dependency-injection": "^4.4.9",         "symfony/expression-language": "^4.4.9",         "symfony/polyfill-ctype": "^1.17.0",         "symfony/polyfill-mbstring": "^1.17.0",         "twig/twig": "^2.9 || ^3",         "williamdes/mariadb-mysql-kbs": "^1.2"     },     "conflict": {         "phpseclib/phpseclib": "2.0.8",         "tecnickcom/tcpdf": "<6.2",         "pragmarx/google2fa": "<6.1.0 || >8.0",         "pragmarx/google2fa-qrcode": "<1.0.1",         "samyoul/u2f-php-server": "<1.1"     },     "suggest": {         "ext-openssl": "Cookie encryption",         "ext-curl": "Updates checking",         "ext-opcache": "Better performance",         "ext-zlib": "For gz import and export",         "ext-bz2": "For bzip2 import and export",         "ext-zip": "For zip import and export",         "ext-gd2": "For image transformations",         "ext-mbstring": "For best performance",         "tecnickcom/tcpdf": "For PDF support",         "pragmarx/google2fa-qrcode": "For 2FA authentication",         "samyoul/u2f-php-server": "For FIDO U2F authentication"     },     "require-dev": {         "php-webdriver/webdriver": "^1.11",         "phpmyadmin/coding-standard": "^2.1.1",         "phpstan/extension-installer": "^1.1",         "phpstan/phpstan": "^0.12.79",         "phpstan/phpstan-phpunit": "^0.12.17",         "phpunit/phpunit": "^7.5 || ^8.0 || ^9.0",         "pragmarx/google2fa-qrcode": "^1.0.1",         "samyoul/u2f-php-server": "^1.1",         "symfony/console": "^4.4",         "symfony/finder": "^4.4",         "symfony/twig-bridge": "^4.4",         "tecnickcom/tcpdf": "^6.4.1",         "vimeo/psalm": "^4.7.0",         "google/apiclient": "^2.0",         "guzzlehttp/guzzle": "^7.0",         "firebase/php-jwt": "^3.0"     },     "extra": {         "branch-alias": {             "dev-master": "5.2.x-dev"         }     },     "scripts": {         "phpcbf": "phpcbf",         "phpcs": "phpcs",         "phpstan": "phpstan analyse",         "psalm": "psalm",         "phpunit": "phpunit --color=always",         "test": [             "@phpcs",             "@phpstan",             "@psalm",             "@phpunit"         ],         "update:baselines": "phpstan analyse --generate-baseline && psalm --set-baseline=psalm-baseline.xml",         "twig-lint": "php scripts/console lint:twig templates --ansi --show-deprecations"     },     "config":{         "sort-packages": true,         "discard-changes": true     } }