Apple

I have a Eufy camera I put on my porch just before the pandemic (so definitely not the latest model), and it does this - get a notification on the Apple TV, with an image in the upper right corner, when someone steps onto the front porch. If I tap the home button on the Apple TV remote while the notification is there, it’ll pause any video and pull the camera feed up full screen.

The camera is also set so it is not uploading anything to Eufy (no monthly charge and no serving as someone else’s remote camera, the way Ring has done occasionally from what I’ve heard) and uses Apple’s HomeKit Secure Video, through the AppleTV (I trust Apple more because security and privacy is one of their selling points - if they got caught doing anything funny with the video, their bottom line would take a massive hit). With that, I can use the Home app on my iPhone to have a live feed of the front porch from anywhere, if I want.

(The irony - got the camera so I could see packages and such on my porch during the day, and then like a month later switched to working from home.)

I ring my ring cameras through homebridge to make them work with HomeKit. No problem viewing all my cameras on Apple TV

ring is amazon so it's alexa. But going to amazon and searching for homekit doorbell (or camera) will bring up several homekit compatible devices.

Alternatively, for things like uniquiti cameras, you can setup a homebridge server that will bring non homekit video feeds into homekit.