Unable to subscribe to Premium plans

I’ve been trying to subscribe to a family plan on my browser for the past half hour but the website (payment.deezer.com) does not react when I press any of the “Start immediately my Deezer Family subscription” buttons. Regardless of the option I choose, the confirmation buttons go absolutely nowhere. I don’t even get a loading symbol, and can continue interacting with the page as if I didn’t press the button at all.

Deezer is my favourite of the streaming platforms I've trialled recently but it’s kind of hard to use it if it won’t let me subscribe! How can I fix this?