What should i use to replace function 'tostring'?

there is 6 different enemies so id rather make it easier if possible name is 'Enemy1,Enemy2' ext 04:24:52.059 - Players.Player1.PlayerGui.Gui.Bars.Bars:8: attempt to concatenate global 'tostring' (a function value)

local hud = script.Parent.Parent
local core = hud.Core
local enemies = hud.FightArea.Enemies
local team = hud.FightArea.Team
local enemy = hud.Enemy
local ally = hud.Ally
	
	enemy["Enemy"..tostring()].Stats.HP.Changed:connect(function()
	if enemy["Enemy"..tostring()].Stats.HP.Value <0 then
		enemy["Enemy"..tostring()].Stats.HP.Value = 0
		hud.Dead.Enemy.Value = hud.Dead.Enemy.Value + 1
		if hud.Dead.Enemy.Value == 6 then
		core.Gold.Value = core.Gold.Value + core.GoldDrop.Value
		enemy["Enemy"..tostring()].Stats.HP.Value = enemy["Enemy"..tostring()].Stats.MaxHP.Value
		core.kills.Value = core.kills.Value + 1
		if core.Kills.Value >= 10 then
			hud.FightArea.nextstage.Visible = true
			end
	end
	end
	enemies["Enemy"..tostring()].HPBar.hptext.Text = enemy["Enemy"..tostring()].Stats.HP.Value.."/"..enemy["Enemy"..tostring()].Stats.MaxHP.Value
	hud.FightArea.Kills.Text = core.Kills.Value.."/".."10"
	enemies["Enemy"..tostring()].HPBar.Bar:TweenSize(UDim2.new(enemy["Enemy"..tostring()].Stats.HP.Value/enemy["Enemy"..tostring()].Stats.MaxHP.Value,0,1,0), "Out", "Quad", 0, false)
	end)

#Nothing

Look at what you're doing. Your tostring is redundant, as it's simply taking nothing as an argument. Remove it and your script will stop erroring from it.