Server RPi GPIO for RFlink

Heey there, I’ve been searching for a while but I cant seem to find the solution to the following:

I recently bought some 433 RF modules through Amazon. I’d like to connect this to the GPIO pins of my Rock Pi that runs Ubuntu with HA server. (If you advice me to run on another OS feel free to say so)
I’d like to control my RF sockets and my RF controlled ceiling fan with this setup.

I can find setups where the Pi (Raspberry or a Rock Pi) functions as a client, but I can’t find a setup where the Pi where the sensors are attached to is the server.

Does anyone know how I can achieve this?
Thanks in advance