Use smartphone from USB webcam?

For online lessons we use Jitsi Meet, because my laptop doesn't have a good camera, I would use my cell phone, but the screen is too small for me. Now I came up with the idea of using my cell phone as a camera (preferably with USB, since my Internet is unstable and I can't be there otherwise). I used standard apps, but they don't work. Unfortunately, I don't know which apps they were because I've already uninstalled them.

Looking forward to answering, greet Jonas

I have always had very good experiences with DroidCam.

No matter whether via USB or WLAN.

Unfortunately DroidCam didn't work for me, but I will try again in a few days. Wi-Fi connection went, unfortunately not usb, tips? Anyway, thanks for the answer

For USB, you also have to turn on USB debugging (developer settings on your phone).

I have

Then I would not know what is going on quickly… Sorry.

I still used IP webcam, which was intercepted with VLC, recorded VLC in OBS and used OBS as a webcam. Complicated but worked…

How do you mean?

IP Webcam is also an app for Android (Apple has no idea).
It makes a livestream which you can open with VLC Media Player.
I record the VLC media player with OBS and OBS can install plugins.
A plugin simulates the output of OBS as a webcam. And this is how I can use OBS as a webcam…

I have DroidCam again, I still had it, it works over Wi-Fi, but it stutters a lot, USB doesn't work, the cable works perfectly, does it make a difference if I don't press "Allow access to phone data" on my cell phone? Otherwise it is connected to the cable of the JBL Flip 5, loads and I can access the data, run DroidCam Client with admin rights, activate USB debugging, and enter the appropriate port