How to use bar defaults

I have spent the past two and a half hours trying to figure out how to make an npc's hp appear when i drop it in from the compedium, as described in the game settings page: " On Default Tokens created by doing a Compendium drop onto the virtual table top, set the Bar 1's value to this attribute. " I've tried setting it to be numbers, hp, hp_max and other things. Any help is greatly appreachiated!

I don't know what game you are playing, but assuming this is 5E, a quick check in a test game shows "hp" as the correct setting.  The snag is that the npc character sheet only has the max hp set, with the current hp being blank (at least it was this way with the aboleth I dragged out).  The way the bar works is that it won't show unless you have a value in both current and max values of the stat the bubble/bar is linked to.  I don't know if this is a bug or not, since I haven't messed with this system to know how it worked in the past.  Once you have the bar linked, enter a value in the bubble for the "current" value and the bar will appear.

I put "hp_max" in both bar 1 fields.