Square thinks I don’t exist
I would just work with Braintree.I was implementing payment system for https://appenlight.com from paypal to some other solution that would not require paypal account. We've evaluated Braintree and Paymill - as App Enlight is european company, so our options were limited. Before Paymill took its time to reply to me (~22 days), I already managed to validate, sign all the papers and actually implement Braintree solution to our application.One more thing at first Braintree support told me they might not be able to work with us because of some restrictions on company legal form by processor bank, but after I have sent them all the documents, everything went fine and got approved. Maybe you can try with them.