How to solve customer_id error in google ads api(python)

Try running the example get_campaign.py in the google ads api. The code was entered as follows

import argparse import sys from google.ads.google_ads.client import GoogleAdsClient from google.ads.google_ads.errors import GoogleAdsException def main(client, customer_id):     ga_service = client.get_service("GoogleAdsService", version="v6")     query = """         SELECT campaign.id, campaign.name         FROM campaign         ORDER BY campaign.id"""     # Issues a search request using streaming.     response = ga_service.search_stream(customer_id, query=query)     try:         for batch in response:             for row in batch.results:                 print(                     f"Campaign with ID {row.campaign.id} and name "                     f'"{row.campaign.name}" was found.'                 )     except GoogleAdsException as ex:         print(             f'Request with ID "{ex.request_id}" failed with status '             f'"{ex.error.code().name}" and includes the following errors:'         )         for error in ex.failure.errors:             print(f'\tError with message "{error.message}".')             if error.location:                 for field_path_element in error.location.field_path_elements:                     print(f"\t\tOn field: {field_path_element.field_name}")         sys.exit(1) if __name__ == "__main__":     # GoogleAdsClient will read the google-ads.yaml configuration file in the     # home directory if none is specified.     google_ads_client = GoogleAdsClient.load_from_storage('C:/Users/GoogleAPI/googleads.yaml')     parser = argparse.ArgumentParser(         description="Lists all campaigns for specified customer."     )     # The following argument(s) should be provided to run the example.     parser.add_argument(         "-c",         "--customer_id",         type=str,         required=True,         help="The Google Ads customer ID.",     )     args = parser.parse_args()     print(args.customer_id)     main(google_ads_client, args.customer_id) 

But I get this error.

 errors {   error_code {     authorization_error: USER_PERMISSION_DENIED   }   message: "User doesn\'t have permission to access customer. Note: If you\'re accessing a client customer, the manager\'s customer id must be set in the \'login-customer-id\' header. See https://developers.google.com/google-ads/api/d ocs/concepts/call-structure#login-customer-id" } 

customer id works fine for google adwords api.

If anyone knows the answer, I would appreciate it if you let me know. Thank you.