Hey there!
Unfortunately it isn't possible to report players via the forum. If you'd like to report a player for breaking our rules, you can do so here: https://truckersmp.com/reports
If you do not have his TMP-ID, you might wanna look at this topic: https://forum.truckersmp.com/index.php?/topic/59284-solved-is-it-possible-to-find-a-truckersmp-id-with-just-a-persons-username/
If the linked topic doesn't help you, let us know ;)!
Kind regards,
Inklink
TruckersMP GM + FM