I’m planning to travel from Milan, Italy, to Geneva, Switzerland, and I’ve come across some information suggesting that I must book my ticket through the app of the departure country (Italy, in this case), rather than the app of the arrival country (Switzerland).
Does this mean I need to purchase my ticket through Trenitalia, or is it possible to buy it through the SBB app instead? What are the differences between the two booking platforms?
Thank you in advance for your help!