Hello KAVYOMEE
You are about to purchase the Swiss Travel Pass. The SwissPass is for Swiss residents.
If you are unable to purchase the Swiss Travel Pass, then you should check with the credit card bank whether your card supports 3D secure ID, a two-factor security element that is required by most European webshops.
If it fails for another reason, try to purchase the Swiss Travel Pass from the Swiss Travel Center, the travel agency owned by SBB and Switzerland tourism:
https://www.myswitzerland.com/en-ch/planning/transport-accommodation/tickets-public-transport/swiss-travel-pass/
Kind regards,
Roland