It is very simple to self-host Monochroma and run your own Instance.
All you need to do is have a Linux server and run these commands:

  git clone https://github.com/monochroma-sp3/Monochroma.git
  cd Monochroma

  ./setup.sh

Not only the setup will take care of everything, but it will guide you into setting up the connection with your Tidal account and it explain everything you need to know.

If you want, you can check out the README.md file on github.