To test if the receiver is working you would need to look at raw data. First you would shut down lircd:
sudo systemctl stop lircd_helper@lirc0
Then you can run mode2 to look at raw data from the IR receiver:
mode2 -d /dev/lirc0
When you press buttons on any remote you should now see lines like:
If you see lines like this you can be fairly sure the IR receiver is working.
To get your remote actually doing anything you would need an appropriate profile for the remote. If none of the bundled ones work you would either need to download one from somewhere like this (and typically you might need to edit it a bit) or you could learn your remote using irrecord:
irrecord -d /dev/lirc0 my-remote.lircd
Following the onscreen instructions.
After that you would select your remote in the remotes section of My OSMC.
You can test key codes being sent to Kodi with the ‘irw’ command - however this will only show any results if you already have an appropriate remote profile selected.