IFrame within Data URI - Audio / Video Access Issue

We are trying to use the IFrame API in a page loaded as data URI string into a WebView2 (MSFT’s new Edge/Chromium browser control) using NavigateToString() in a C# application. Everything works fine, apart from access to audio and video when connected to a Jitsi Meeting. When trying to activate either the microphone or camera, we get an error message saying “Cannot read property ‘getUserMedia’ of undefined”.

We have the suspicion that it might be because the data URI isn’t loaded using HTTPS, but the IFrame is using HTTPS and according to our knowledge that can cause issues with WebRTC access in Chromium. Can anyone confirm this, or are we doing something wrong?

<html>
    <head>
        <meta charset="utf-8" />
    </head>
    <body>
        <div id="placeholder" />
        <script src='https://meet.jit.si/external_api.js'></script>
        <script type="text/javascript">
            var domain = "%%_DOMAIN_%%";
            var options = {
                configOverwrite: {
                    startAudioOnly: false,
                    startWithAudioMuted: true,
                    startWithVideoMuted: false,
                    disable1On1Mode: true
                },
                height: "100%",
                jwt: "%%_TOKEN_%%",
                parentNode: document.querySelector('#placeholder'),
                roomName: "%%_ROOM_NAME_%%",
                width: "100%"
            };
            var api = new JitsiMeetExternalAPI(domain, options);

            api.executeCommand("subject", "%%_SUBJECT_%%");
        </script>
    </body>
</html>

The error message in the console reads:

2021-03-12T23:06:49.690Z [features/base/tracks] Failed to create local tracks Array(1) TypeError: Cannot read property 'getUserMedia' of undefined
at RTCUtils.js:994
at new Promise (<anonymous>)
at z._newGetUserMediaWithConstraints (RTCUtils.js:993)
at z.<anonymous> (RTCUtils.js:1367)

And if not using HTTPS indeed is the issue and it can’t be fixed, is there any comprehensive example of the low-level JavaScript API for Jitsi Meet? We thus far failed to implement the same functionality as with the IFrame API shown above.