Can't add Easyjet Plus Card to wallet

I cannot add my Easyjet Plus card (a membership card) to my wallet.

I know a few people have had this issue in the past, but I'm yet to actually come across a solution. I can't get hold of Easyjet to get their help, I'm waiting on a reply to my email.

I have the Easyjet Plus Card email, with the link to add my membership card to the Apple Wallet. But when I click on it, the page; wallet.pct.tech does not respond. It freezes and then says "Safari cannot open the page because it could not establish a secure connection to the server."

I've tried 3 different iPhones and a MacBook. Different browsers and different internet connections - same problem.

Any one had this and solved it? It's very frustrating.

Cheers