Thank you, I wasn't sure where to ask my question, I'll copy it to the Linux forum.
dear god... his response above was incredibly unhelpful. A lot of text, and nothing useful.
If you're buying a IP CAM which is usually wifi or ethernet based, that cam is likely going to support RTSP.
The issue with cheap cams like wyze, amcrest, foscam, etc is their frame rates, resolutions, mics color definition and all the important stuff is often very poor - because you're not looking for definition, just confirmation that yes - something happened.
Get a good webcam, or a Hikvision bullet cam with 60fps. These cams are okay for what you want to do.
Being "remote" to you is a issue. You'll have to setup the streambox on site to access local IP's.
A url like this is a valid wyze cam RTSP url:
rtsp://Admin:Admin12345@192.168.1.20/live
you can add it by clicking the + button in sources, and choosing media source.
uncheck "Local", and paste the line in your "input".
This ip address will not be the same as yours, nor the username and password. heck, even the whole URL might be different. you're going to have to figure it out on a cam by cam basis, depending on what you bought.
As for your stream... your computer needs to be powerful, support NVENC for video encoding, and not look like crap to keep people watching. Audio needs to be good. Audio needs to be in sync with video. lighting needs to be good.... and uptime is important if you plan to go for 24/7... but i think Facebook only supports 12h sessions... so you'd need to automate and restart the session.
There's a lot to consider. Obs is good for including Overlays, custom graphics and audio mixing.
Get the stupid direct-to-facebook cam if you can't configure or are unable to understand how to configure this... but it's gunna be garbage.
There.
Where's my five bucks?