ok, that fine admin can assign role to user. Now what do you want to do
If you want to know how to change a user's password then check this post
https://www.outsystems.com/forums/discussion/37611/how-to-update-user-password/
If you want to know how to assign role to the users then follow this documentation
https://success.outsystems.com/Documentation/11/Developing_an_Application/Secure_the_Application/User_Roles/Create_and_Use_Roles