Since I’ve seen some people asking how to do it, and getting the answer that they cannot… Here is a very simply, but sometimes tedious way of placing an NPC wherever you want, WITHOUT the use of scripting:
Simply put an NPC blocker attribute or block attribute on every tile except the tile where you want to place the specific NPC. Then load up the NPC onto the map, since it can not go anywhere it will be in the one space you left open which is where you want to place it.
Now to get it facing the right direction simply spam /respawn until its facing the way you want it.
After this, simply lift the NPC blocks off the other tiles and make sure not to /respawn again.