I am trying to add this to the GUIShop plugin. I've tried these commands:

"callheli pos $player.id"
"callheli pos \"$player.x $player.y $player.z\ 1""

Both result in [HeliControl] You must supply 3 args for coordinates! message in the console. What am I doing wrong? I read you can supply the player name, which is why I did it the first way and the second way should provide 3 coordinates.

I believe the issue are the quotes surrounding the coordinates in your command. This plugin expects 3 individual coordinates, rather than one coordinate string. If you split them into 3 separate arguments, such as this, it should work:

"callheli pos 1482 150 1322"