WTH can't I get streaming to chromecast to work

I have a bunch of Unifi camera’s and two Doorbirds. All are connected to Zoneminder and then Home Assistant. i also have some other camera entities like Buienradar. I can’t get any of the camera’s to stream to my chromecast from Home Assistant, neither through Zoneminder nor directly. i have tried a bunch of ways, but none seem to work.

How the heck am I supposed to configure this?

I’ve tried hard to do this too. What’s your config?

I have no config for this right now as I simply cannot get it to work.