Hello Uberundo
It depends on the ticket type, country, and point of sale, whether they are available in the SBB Mobile app or not.
For Italy, they are not available in the app, as Italian rail tickets use another technical standard, and this is why they cannot be displayed in the SBB Mobile app. Likewise, SBB conductors use the Italian railway’s ticket control app to check your international ticket. Whether you have got it as PDF or hardcopy (printed ticket), both is fine.
Kind regards,
Roland