I can't add a card

I go to checkout, and fill in my card info, but the add card button remains unclickable.

Hi there wjlambrecht, welcome to Demiplane! I’m sorry to hear you’re experiencing this. Could you let me know a couple extra details that will help us hunt down what’s happening here?

What browser and device are you experiencing the issue on? (Eg. Chrome on a Windows laptop, or Safari on an iPhone, etc.)