MixedReality-WebRTC is a collection of components to help mixed reality app developers integrate audio and video real-time communication into their application and improve their collaborative experience
There is no ARM64 version of this library available yet.
414 is currently the status of ARM64 development. Seems to have been inactive for a while. This thread (and some others) describe some of the details required if you want to attempt an ARM64 build, but it's not trivial.
How can i have a mrwebrtc.dll(ARM64).