I can't add a card

I've been a subscriber for a while. I've been having trouble updating my card information for a while but it hasn't been a problem until now. When I try and go to the subscriptions page it says it'll charge the card ending in blank but there are no numbers and there's no way for me to add another card.

Does this page not work? https://line-of-action.com/user/billing-method Reached by clicking the gear icon next to the billing info.

It worked once I copied and pasted the link but the gear icon wasn't showing up. Where it says charge the card ending in [blank] it doesn't show a card number for me to click to update. 

I'll just save the link in my notes app or something in case this happens again :)