Reeta
If you’re logged in on sbb.ch, you’d find the option you’re looking for on the page appearing after clicking ‘select tickets’ for a specific connection, where you can chose all available ticket options such as 1st / 2nd class.
Now select that pen symbol next to your name, that’s where you specify who you are buying tickets for, inlcuding relevant details such as age or applicable travelcards.
