#you need ffmpeg to use obs on ubuntu
sudo apt install ffmpeg

# get the repository
sudo add-apt-repository ppa:obsproject/obs-studio 

#install obs studio
sudo apt install obs-studio

 sudo apt install ffmpeg
 sudo apt install v4l2loopback-dkms
 
 sudo add-apt-repository ppa:obsproject/obs-studio
 sudo apt update
 sudo apt install obs-studio