I am happy to share a script and configuration instructions to control a Mopidy server from an infrared receiver: mopidyir.
In my setup, the Mopidy server runs on a Raspberry Pi 5 and the IR receiver is provided by the AUDIOPHONICS DIGI PRO Digital Interface WM8804 hat also used to output the music stream to a an amplifier. The amplifier has a remote control that can control multiple devices.
Nothing clever or elaborated in that script…