Hello Heraldo95
You can also purchase travel passes from the Switzerland Travel Center.
However, the SBB webshop indeed requires 3D secure ID, as many web shops in Switzerland, too. It is for your own security, as SBB is one of the most used web shops in our country.
Yesterday, I helped three tourists from the U.S. to buy a ticket from an SBB vending machine; the total amount was CHF 284. One of their credit cards requested a PIN, they even didn’t know the PIN as they never had to enter it before. They used another card; this card was accepted by the machine right away, no PIN, nothing. A purchase of CHF 284 without any security check - unbelivable from a Swiss perspective.
Kind regards,
Roland