I should assume about older model like this. do you have any lags or problems?
https://www.amazon.com/Elgato-External-Capture-1080p60-ultra-low/dp/B07XB6VNLJ
You feed an hdmi into your elgato capture card, and then a usb from the card to your computer, which captures with OBS or something similar. There is a pass through port for an hdmi cable to get the video to your TV.
If I remember right, you’ll need a device to split the audio off of your video feed and that will go separately into your computer.
This model would be the one to get https://www.amazon.com/Elgato-External-Capture-1080p60-ultra-low/dp/B07XB6VNLJ/ref=mp_s_a_1_3
Marco talked about video capture on an M1 computer on ATP awhile back. I think he is using 3 Elgato HD60 S+ devices to capture 3 laptop sources.