Bitfocus Companion and Elgato StreamDeck on a Raspberry Pi 4 Model B.
Bitfocus has some great directions for installing Companion on a Raspberry Pi 4.
Extras:
Enable SSH on the Raspberry Pi
Get Putty - a free ssh and telnet client for Windows
Installing Companion Directions:
Companion on the Raspberry Pi - A Primer
Manual Install on Raspberry Pi
* Updating Companion directions are here: On Github
The Official Directions Getting Started: