I am following this tutorial to enable RDS postgres IAM auth for the master user: https://aws.amazon.com/premiumsupport/knowledge-center/users-connect-rds-iam/
The master user currently uses password auth. One thing I am not sure about is: if I enable the IAM auth for this master user, can I still use password to talk to RDS? Can we have these two types of auth working at the same time?