Oracle Autonomous Database Enable IAM database password for users on secondary domains

Is it possible to enable OCI IAM database password for users that are created on a non-Default OCI Domain?

I try creating a user as such:

CREATE USER username IDENTIFIED GLOBALLY AS 'IAM_PRINCIPAL_NAME=mydomain/username';

And with the following IAM policy created:

Allow group 'mydomain'/'mygroup' to use autonomous-database-family in compartment mycompartment where target.database.id = '{atp-ocid}'

I am not able to login using the IAM database password this way.