Tricky question,
This requires to interfere in the login mechanism. Using custom Java this can be done: https://apidocs.rnd.mendix.com/8/runtime/com/mendix/core/action/user/LoginAction.html
My approach would be;
My Java knowledge is limited, so that you have to sort out yourself using the runtime documentation
Standard functionality. See https://docs.mendix.com/refguide/translatable-texts#1-introduction