Doxy.me uses Stripe to process credit card payments from your patients. You can bill your client before a session. You can charge your clients your normal fees or adjust as you see fit.
To set up stripe log into your clinic account, click "account settings" and then click the "extensions" tab. Then click payments at the bottom and it expands and takes you through how to set up payments. Once a meeting has started you'll be able to select the payment button on the left side of your dashboard and input the amount to charge. Then the patient gets a popup that lets them enter in CC details and be charged.
Stripe is 2.9% + .30 cents per transaction and once you have the patients credit card info from 1 payment you can go into your stripe dashboard and charge them for additional visits without the patient needing to enter their CC again. Doxy.me does not receive any fees from Stripe.
Billing insurance is specific to state laws at the moment. Head to the American Telemedicine Association for specific information about policy. You can find that here.