Hello,
To be able to have HCT trailers everywhere, first install this mod: https://steamcommunity.com/sharedfiles/filedetails/?id=1766128598
Then get on ETS2 and install this mod via the mod manager on the profile. Buy the trailer and then save the game and then you're good to go.
If you want to use it on TMP, load the save you saved your HCT trailer on.