Headway, Tava, and Grow Therapy are the billing and scheduling companies I use. 

You can find my Profile links for each of them here: 

Headway: https://headway.co/providers/sally-dorpfeld

Tava: https://care.tavahealth.com/providers/sally-dorpfeld

Grow Therapy: https://provider.growtherapy.com/book-appointment?id=18177&utm_source=provider-sourced&utm_medium=booking-link&utm_campaign=provider-dashboard