Hi @Adrian Govender, here is my suggestion, firstly you will need to create users in OutSystems user table with the same username, then when the users try to login, first authenticate them using the external table (if you also have roles in external table then check the authorization as well), once they are authenticated search for them in the OutSystems users table using the username (if user is authenticated in external table and not found in OutSystems, create the user in the same flow), then log the user in in OutSystems using the "Login" server action form system module, it only needs the "UserId" for login.

Note: Complete all this in one single server call for security.

Note: If the users can only update their passwords from OutSystems, then you can also create the users with same password and use the normal "DoLogin" server action.

Note: If you don't want users in OutSystems user table you can create your own user provider module, for this please check out this forge component Most Simple User Provider.

Thanks
Gitansh Anand