https://community.roonlabs.com/t/ropieee-on-raspberry-pi-4/91848
This is really easy. You download the free RoPieeeXL software to your computer. Then you use Etcher to burn it onto a micro SD card. You stick the SD card in a Raspberry Pi 4 and put the RPi4 in a FLIRC fanless case. It takes about 10 minutes for the software and 10 minutes for the hardware. In no more than 20 minutes, you have a Roon bridge for your Dragonfly.