Do I need an amazon.es account to pay balance in spanish market?

I have a UK seller account, and have sold across europe with it, however I had a return from spain which led to the account going into the negative in that market. I can only pay the balance by switching seller central to the spain tab, then going to payments and my card details and everything are ready with the pay now button.

The problem? As soon as I click pay now it opens an amazon.es sign in link and I cannot proceed without signing in, my UK details do not work. I was under the impression I could do everything in the EU from my UK seller account?

Any help would be appreciated.