Hello dmricecpa
Good evening.
You have to make seat reservations with the Gotthard Panorama Express directly, they are mandatory.
https://www.sbb.ch/en/leisure-holidays/trains-boats/panorama-trains/gotthard-panorama-express.html
We are a customer support page run by volunteering travel experts, not the SBB Customer Service. Sorry, we do not contact anyone by phone or e-mail, neither does SBB.
And, for data protection and privacy reasons you should never ever leave personal information or ticket details on a publicly accessible website.
Kind regards,
Roland