Jeemoiqueeck90
Agreed, the SWISS (Intl. Airlines) app won’t let you do that. 😊
Neither will the SBB Mobile app directly. However under Profile > Personal Data it will redirect you to swisspass.ch (via browser), which is the only place where your monthly or yearly SBB passes including personal+login data can be managed.
You might prefer to do this from a PC with its bigger screen anyway.