Azure SQL - is it possible to assign CREATE PROCEDURE permission for the master database?

I am trying to add a stored procedure to the master database (I deliberately am trying this for the master db) on Azure SQL. Is this possible? I suspect the answer is "no", but I'd like to see some confirming documentation on it if that is the case. What I've tried so far: Here's the procedure (just as a test): CREATE PROCEDURE dbo.blah AS RETURN 0; I've tried the above using the admin login, and it failed: Msg 262, Level 14, State 18, Procedure blah, Line 2 [Batch Start Line 21] CREATE PROCEDURE permission denied in database 'master'. I then tried to create another login and user and then assigned them to the "dbmanager" role and tried the create procedure again - same failure.