SaaS app for a doctors appointment

I'm looking to build a saas web app that allows doctors to create their website (on the app subdomain) with appointment functionality. The patient can come to their website to book an appointment with online payment. The interface of the web will be professional yet clean.

I've searched the web for any existing solutions in this niche but I'm unable to find so. Therefore I want to take your input in this regard.

Do you see any potential issues with this idea?