SL payments: so where do I have to click to allow using dollars in the account?

It tries to bill my paypal, which is silly, because there's enough money in the account. And also it suddenly has a problem with my paypal, which it didn't before. It worked for years. Now where I added the needed information they asked for, it stopped working. fuckers.

Ah, found it.

I can click PAY NOW, and there it offers me to use the available money.