Hi,@Channabasawa Nagur Welcome to the Microsoft Q&A platform, thanks for posting the question and for using Azure Services.
Can you please confirm if you are using a Single server or a flexible server?
If auth_user is set then any user not specified in auth_file will be queried through the auth_query query from pg_shadow in the database, using auth_user the password of auth_user will be taken from auth_file, if the auth_user does not require a password then it does not need to be defined in auth_file.
Direct access to pg_shadow requires admin rights.
Regards
Geetha