Smart payment buttons (PayPal & Venmo) with Braintree integration

If you Google “smart payment buttons” you’ll see the PayPal and Venmo buttons that allow customers to pay with “one click”, meaning the venmo button will show up at checkout and automatically pulls the money from their venmo account without them having to fill in all of their information to pay. I have already set up a Braintree account and have been APPROVED by them, I just don’t know how to develop these buttons. I’m not looking for a developer to tell me what they can’t do (you know the type, they come in all occupations), I’m looking for one who can make this happen). I’ve done the initial hard work of getting approved on Braintree, now I need someone to finish the job.