With a little fucking around I’m fairly sure you could do it on the phone itself via termux.

There’s a repo for it maintained by ghost, but you have to do the install and setup yourself. Can’t vouch for reliability, never used it.

Pretty sure if you self host your own ghost install it’s already available.

I have a terrible feeling it’s a compromised webcam.

I suspect that’s kind of the point, or at least works in their favour. If you don’t know about it, you’re probably pretty new here and therefore a better candidate for a victim.