Hello Subhash,
Could you please explain in little more details what are your requirements.
Whenever you create new application web, reactive or mobile. OutSystems automatically create Login screen for you In common workflow. You just need to create new application, one default module get created automatically. You can make any customization on this screen as per your requirement. All login logic is also written here, you don't need to do anything until there is not any specific requirement.
Apart from this for username, password are the field from System-> User table and both are of text type. For creating new user into the system you just need to call CreateUser() server action in your logic.
