VMatrix doesn't work?

I tried to add an ulx command which changes the headsize, but it doesn’t work

function ulx.bubblehead( calling_ply, target_plys, scale)
	for k, v in pairs( target_plys ) do
		if v:IsValid() then
				local matr = v:GetBoneMatrix(6)
				matr:Scale(Vector(scale, scale, scale))
				v:ManipulateBoneScale(6, matr)
	ulx.fancyLogAdmin( calling_ply, "#A set the headscale for #T to #i", target_plys, scale )
local bubble = ulx.command( "Fun", "ulx bubble", ulx.bubblehead, "!bubble" )
bubble:addParam{ type=ULib.cmds.PlayersArg }
bubble:addParam{ type=ULib.cmds.NumArg, default=1, min=0, hint="multiplier" }
bubble:defaultAccess( ULib.ACCESS_ADMIN )
bubble:help( "Set the head scale of a player." )

Use code tags please and are you getting any errors?

Figured out myself,
just used

 v:ManipulateBoneScale(6, Vector(scale, scale, scale))