Why can't I link my Affirm App despite multiple login attempts?

[hubcitysales]

It ask to log in to affirm and when I do it just loads the same login screen again. I’ve tried from my phone, iPad and desktop and still the same thing happens

[Lulusglowbox]

I am having the same problem, Affirm says we have to put in our code on our website but I can’t figure out how to do it without messing up my theme.