If my certificate has expired and I don't want to change my display name, how can I get a new certificate to continue account verification?

I added a business phone number on the WhatsApp administrator page, and it says that the status of the phone number is 'waiting' and requires phone number registration. I'm trying to follow the guide, so should I follow the document guide 'Migration from On-premises API to Cloud API'? Is there any way to proceed with phone number registration and certificate registration on the WhatsApp administrator page without that process? I'm going to send an authentication message to my customers in different countries via WhatsApp. At this time, I'd like to conduct a shipping test to check the actual billing system, so I'd appreciate it if you could give me a guide on how to register a business phone number. Please reply as soon as possible.

The link to "View Best Practices" on the image points to https://developers.facebook.com/docs/app-review/resources/sample-submissions/server-to-server#providing-verification-details however traversing to that location ends in a 404.

On 2024-12-11, Cloud API had an outage. The send message api was returning 500, "requests.exceptions.HTTPError: 500 Server Error: Internal Server Error for url: https://graph.facebook.com/v21.0/462959503569059/messages".
After the service was restored, some customers informed us that they were receiving old messages. Upon investigation, I found that we were receiving message statuses, meaning that even though the API returned a 500 error, the messages were still being delivered to the customers. This caused problems for us because we didn’t expect the messages to be delivered. Has anyone else experienced this issue?
What is the correct way to prevent this, or was it truly an error on Meta's part?

I have created a short term token to grab instagram business account data from https://developers.facebook.com/tools/explorer/ with following permissions

pages_show_list business_management instagram_basic pages_read_engagement pages_read_user_content 

and then i extend the short term token to longterm from https://developers.facebook.com/tools/debug/accesstoken/?access_token=SHORT_TERM_TOKEN=v21.0

But when i request instagram for grabbing media

curl -X GET "https://graph.instagram.com/me/media?fields=id,caption,children,permalink,media_type,media_url,username,thumbnail_url,timestamp&access_token=LONG_TERM_ACCESS_TOKEN" 

It throws error

"Sorry, this content isn't available right now"

What am i missing?