Hello YEJKINKIM
Welcome to the SBB Community. A hello is always appreciated.
Provided you have entered the e-mail address correctly, and there is no e-mail in your SPAM folder:
The payment was NOT successful. Check again with your bank, they should have activated 3D secure ID for your card.
https://community.sbb.ch/d/36523-payment-could-not-be-finalized/4
We suggest making purchases with a customer account. By doing so you can find the tickets in the list of orders and even in the SBB Mobile app.
Kind regards,
Roland