As it has been mentioned here, unfortunately there is a sever bug in WKWebView in iOS preventing using getUserMedia , stopping apps like Chrome, Firefox, or any cordova or capacitor based apps from being able to use the media stream.
Is there an native equivalent thing in iOS as getUserMedia to use it as a workaround?
Could this be used as an alternative, to access the microphone?
I am using such functionality for a voice chat using WebRTC.
As you mentioned WKWebView I assume you are using cordova or something similar to show your existing webapp. If that is so, this might help you: https://github.com/cordova-rtc/cordova-plugin-iosrtc - works perfectly and support by the creators is awesome.