Hello Phowoigoa95
Firstly, good day and welcome to the SBB Community.
Adding a travel card, travel pass, or ticket after purchase is not possible. Only those that were purchased directly through SBB using a customer account will appear in the SBB Mobile app.
You are welcome to use the PDF.
Whenever you use e-tickets or a PDF ticket, you must show your physical passport (no copies, no photos on smart phones) together with your ticket / travel card.
Kind regards,
Roland