Long term credentials for IAM identity user?

Everything IAM related suggest using IAM Identity management to create user, assign groups and manage permissions, however when a user is created (even a PowerUserAccess) the command line credentials given are only short term, and IAM Identity unlike IAM does not allow you to control how long credentials are valid.

Is there a way to set a PowerUserAccess or higher to have longer term credentials?

The SSO solution does not work for poweruser (terminal HPC) users as browsers do not launch.

Seem if this functionality can not be used or added it a huge limitation to using IAM identity.