Seeed S2105 soil/moisture/ec

As a non-programmer, I am trying to setup a Seeed S2105 soil/moisture/ec sensor on a RAK7244 gateway running chirpstack v3. I have other sensors running and sending data to servers using MQTT.
I can’t seem to get the device to join the network even though I’ve been putting in the EUIs and key. Can anyone help with this? Thanks in advance.

Under the frames tab of your gateway (in the ChirpStack UI), do you see the join-request?

Thanks for answering brocaar. By dumb luck somehow I have the S2105 successfully joined on the network, and it seems to be broadcasting correctly every 60 minutes.
The problem now is the codec needed to decode the data. I see there is one for TTN but I haven’t been able to get it to work for chirpstack. I have added the code:

function Decode(fPort, bytes, variables) {
return Generic_Decoder(bytes, fPort);
function Generic_Decoder(port, bytes) {
But this doesn’t seem to work. I saw this suggested in an earlier quote but it isn’t working for me. I must have something missing.
Any ideas about this? Thanks.

Problem solved with a slight modification of the TTN decoder.