IAM authentication for RDS secured behind secrets manager

Hi, We have mysql RDS which is behind secrets manager and I have created IAM profile which includes EC2 and RDS full access polices and mysql is enabled for IAM authentication. How do we connect from java application i.e tomcat context file using IAM authentication for RDS , it works using secrets manager via access key and secrets access key. Our clients want to connect to RDS using IAM but RDS is behind secrets manager.

Thanks, Easwar.