Hi @Kasia
Thank you for your request.
SBB Mobile permits the purchase of tickets for other people, without being obliged to purchase a ticket for oneself.
The first Mobile Ticket is automatically issued to the person who is logged into the App. You can add further passengers or change passenger details in the step «Ticket Options». Please click on «Edit travelers».
Information for the SBB Mobile may be found on www.sbb.ch/en/mobile
Best regards
NicolasK