Everyone else is saying it's impossible because copyright and ownership, but I guess it must be a Mac thing, because I'm not at all having this problem on PC. Amazon, Hulu, Netflix, Xfinity... I've streamed anything and everything without problem.
Mind you, I'm almost always sharing the whole screen, and not the lone application. No idea if that makes a difference.
I do occasionally have to stream certain things using a screen capture virtual camera (and then on the application, stream my "webcam" which is actually the virtual camera). On Windows, I'd use OBS + VirtualCam. From a quick search it looks like you can do that on Mac using CamTwist.
Sorry that I can't be more helpful. I just want you to know that it's not 100% impossible to stream those sites.
Allow me to introduce you to Netflix party
I have to check out metastream, I haven't heard of it and I expect one day I'll wanna watch Disney+ with a friend that lives in mexico.
I've email Kast about it, and this is their reply:
You should be able to use a file extractor program (such as https://www.7-zip.org/) to extract the files from the installer, and run the Kast.exe program inside.
Using winrar to extract the file should be fine as well. This works for me and I hope to would work for others too.
Did Kast buy Rabbit?
No, Kast bought certain assets of Rabbit. Unfortunately, Rabbit went out of business and had to layoff their entire staff. Check out this link to learn more: https://kast.gg/kast-acquires-rabbit-assets-press-release.html.