I have an error popping up NPCactivity is not a valid member of Model is it possible to solve it I am waiting for your answer This is a shield for my character

here is the script wait() local sp = script.Parent local shield = sp.Shield local auxhealth = sp.AUXhealth local Humanoid = sp:FindFirstChild("Humanoid") local DamageAbsordPerShield = 350 local CurrentShieldHealth = DamageAbsordPerShield

local tempinvincible = false

if Humanoid and Humanoid.Health ~= 0 then

Humanoid.Health = Humanoid.MaxHealth
local CurrentHealth = Humanoid.Health

Connection = Humanoid.HealthChanged:connect(function(Health)
	local Change = math.abs(CurrentHealth - Health)
	if CurrentHealth > Health then
		
		if shield.Value >= 1 then
			
			Humanoid.Health = Humanoid.MaxHealth

			shield.Value = shield.Value - Change
			
		elseif auxhealth.Value >= 1 then
			
			Humanoid.Health = Humanoid.MaxHealth

			auxhealth.Value = auxhealth.Value - Change
			
		elseif auxhealth.Value <= 0 and tempinvincible == false and script.Parent.NPCactivity.Fury.Value == false then
			tempinvincible = true
			
			repeat
				wait(1)
			until script.Parent.NPCactivity.Fury.Value == true
			
			tempinvincible = false
			
		elseif tempinvincible == true then
			
			Humanoid.Health = Humanoid.MaxHealth

			script.Parent.HitPoints.Value = script.Parent.HitPoints.Value - Change
			
		else
			
			--Do nothing...
			
		end
		
		
		
	end
	CurrentHealth = Humanoid.Health
end)

else

end