MediaDevices.getUserMedia for web extension not working

We are upgrading our web extension to support -desktop (screen, audio, video) capture.

We already did same thing for chrome and now doing for firefox addon.

As per guideline we are supposed to use this API - navigator.MediaDevices.getUserMedia

But when I run this API in content script(web page is having http domain) or background page of web extension it throws following error -

[Deprecation] getUserMedia() no longer works on insecure origins. To use this feature, you should consider switching your application to a secure origin, such as HTTPS.
message:"The request is not allowed by the user agent or the platform in the current context."
name :NotAllowedError

Most of our users use http based website, so any suggestion/solution ?

PS - Same API works within content script (if website is hosted on https domain).