I want to create new user using admin user, however, get error doesn't have permission which probably no sysadmin roles due limitation from aws

so is there another way to create new user using my admin user?
I want to create new user using admin user, however, get error doesn't have permission which probably no sysadmin roles due limitation from aws

so is there another way to create new user using my admin user?
It is not possible in AWS RDS - SQLSERVER
Link: https://docs.aws.amazon.com/pt_br/AmazonRDS/latest/UserGuide/CHAP_SQLServer.html