Say for example, I sense I may be in danger, and I want to turn on video and audio recording on my phone and have it sent to my self host server, is there software for it?

I was thinking of using Nextcloud Talk and then recording my session if possible.

Even better if I can share access with someone I trust.

i dont know exact software, but you could maybe set up an rtmp server (nginx) at home, either with ports open or vpn home (tailscale) and stream video to the server from your phone (does that exist?). then have ffmpeg constantly looking for content on the rtmp server and saving it to a shared place like nextcloud or syncthing the folder to the trusted friend.

Maybe something like https://owncast.online/ or https://github.com/bluenviron/mediamtx

You could set it up to record and maybe even use a hook and some cli signal client to send a message with the stream url to one of your friends?

These look great, thanks!