Credit Card Processing Freezing

I can not get to anyone who can actually help with QB 2020 for MAC. The problem I am having right now is when I create an invoice and choose Accept Credit Cards......when the window "connecting to Intuit" opens, there is a login box for my merchant Account, but I can not click anywhere inside the window......it will not cancel and I can not sign in....I have to Force Quit to get out. Please help.....someone.....I need to invoice customers and at this point I can not process Credit Card payments for my customers