I was trying to try out billboard GUIs and ran into some problems. The are not like regular GUIs and I have no idea how to center one Frame to into another Frame if the hierarchy is BillboardGUI => Frame => Frame (=> means 'parent of')

For some reason, I can't change any property of the Frames when I launch Solo or Server Test This is my code

game.Players.PlayerAdded:Connect(function(player)
	local boardclone = board:Clone()
	local background = boardclone:WaitForChild("Background")
	local energy = boardclone:WaitForChild("Energy")
	
	background.BorderSizePixel = 0
	background.Size = UDim2.new(1, 0, 1, 0)
	background.BackgroundColor3 = Color3.new(0,0,0)
	background.Style = Enum.FrameStyle.RobloxRound

	energy.Size = UDim2.new(.95, 0, .95, 0)
	energy.BackgroundColor3 = Color3.new(0, 255, 0)
	energy.Position = UDim2.new(.5, 0, .5, 0)
--	boardclone.Parent = game.Workspace[player.Name].Head
end)