Android video calling application. Where there are 2 types of users: Clients and worker. The client will buy credit through cryptocurrency API and will be able to call the worker.

I'm looking to develop an Android video calling app for a wide variety of users. This application will be used by two main types of users: Clients and Workers. Customers will have the opportunity to purchase credits through an integrated cryptocurrency API. They can then use those credits to call and connect with workers. Workers will be able to withdraw their earnings through Binance Pay or a local bank account. To withdraw money they need a sponsor who will have a web panel. There will also be an admin web panel where there will be many functions and one of which is also to create sponsors. The features I'm looking for in this app are video calling with chat functionality as well as video calling with screen sharing capabilities. I would like to integrate USDT cryptocurrency as a financial asset for API integration. For the purposes of this application, I would like to expect that more than 100 users will be able to use the application simultaneously.