Hi @0x3N3JVhPUV ,
Welcome to Microsoft Q&A forum.
As I understand, you are getting error: FATAL: password authentication failed for user in Azure Database for PostgreSQL.
As mentioned by you, document https://video2.skills-academy.com/en-us/azure/postgresql/flexible-server/troubleshoot-password-authentication-failed-for-user has been referred and did not help in your case.
If you're still facing issues after following the guidance provided, please don't hesitate to file a support ticket.
Thanks