How to send information from the far side of the Moon to the Earth?

You need a satellite that has a view of the landing site and the Earth. There are several possibilities for doing this. According to the NASA Space Science Data Coordinated Archive, the communications are relayed through the satellite Queqiao which is in a halo orbit around the Earth-Moon L₂ point.

You could also have a satellite in lunar orbit, transmit data from the lander while it's over the far side, transmit data to Earth while it's over the near side.

Or relay via a satellite in interplanetary space, etc.