a message for the support person to enter her attendant number (User ID on the backend).
a text input
a "Next" button
Error messages
When the next button is pressed the app needs to check if there is such user id in the backend, if not found or if the server is down, the user should receive the error message in the same screen and the next button is re-enabled for her to try again.
fczuardi
commented
7 years ago 
A welcome screen with:
Error messages
When the next button is pressed the app needs to check if there is such user id in the backend, if not found or if the server is down, the user should receive the error message in the same screen and the next button is re-enabled for her to try again.