WebRTC for Real Estate Website

We need a WebRTC application (Audio only )for our real estate website where users (property owner and users) can make ''Voice call'' to each other, but with a group call to Admin' account. For example, user A will call user B, firstly call will be connected to ''Available'' admin user(call will not go Admin user who is already in a call), if Admin user accepts the call then it will be connected to user B. So each will be a Group call between, user A, user B, and Admin user. 1)- There will be ''Call'' button on each property detail page and within dashboard of each user. 2)- There will be a History feature which will contain all log of calls including missed calls from other users. 3)- A number will be assigned to each user within dashboard to make call to other user by entering the number of other user. 4)- It will be a separate wordpress plugin which be installed and uninstalled without any issue with the website.