Humanoid is not a valid member of Model? anyone know how to fix this?

I'm scripting from a youtube tutorial and I'm making a tower defense game and for some reason I have a error "Humanoid is not a valid member of model Workspace.Towers.Slinger? (also the error is on line 63)

(towers is my folder where I put my towers in and slinger is the towers name) does anyone know how to fix?

https://youtu.be/wy-Z-xBYbes
that is the youtube video I used for the script and the error is on

local y = result.Position.Y + towerToSpawn.Humanoid.HipHeight + (towerToSpawn.PrimaryPart.Size.Y / 2) is the error

local ReplicatedStorage = game:GetService("ReplicatedStorage")
local RunService = game:GetService("RunService")
local UserInputService = game:GetService("UserInputService")

local towers = ReplicatedStorage:WaitForChild("Towers")

local camera = workspace.CurrentCamera
local gui = script.Parent

local towerToSpawn = nil
local function MouseRaycast(blacklist)
	local mousePosition = UserInputService:GetMouseLocation()
	local mouseRay = camera:ViewportPointToRay(mousePosition.X, mousePosition.Y)
	local raycastParams = RaycastParams.new()
	
	raycastParams.FilterType = Enum.RaycastFilterType.Blacklist
	raycastParams.FilterDescendantsInstances = blacklist
		
local raycastResult = workspace:Raycast(mouseRay.Origin, mouseRay.Direction * 1000, raycastParams)

	
	return raycastResult
end


local function AddPlaceholderTower(name)
	
	local towerExists = towers:FindFirstChild(name)
	if towerExists then
	    towerToSpawn = towerExists:Clone()
		towerToSpawn.Parent = workspace.Towers
	end
end

gui.Spawn.Activated:Connect(function()
	AddPlaceholderTower("Slinger")
end)

UserInputService.InputBegan:Connect(function(input, processed)
	if processed then
		return
	end
	
	if input.UserInputType == Enum.UserInputType.MouseButton1 then
	
	end
end)

RunService.RenderStepped:Connect(function()
	if towerToSpawn then
		local result =MouseRaycast({towerToSpawn})
		if result and result.Instance then
			local x = result.Position.X
			local y = result.Position.Y + towerToSpawn.Humanoid.HipHeight + (towerToSpawn.PrimaryPart.Size.Y / 2)
			local z = result.Position.Z

			local cframe = CFrame.new(x,y,z)
			towerToSpawn:SetPrimaryPartCFrame(cframe)
	    end
	end
end)

Are you sure you have a humanoid inside the Model? If yes, try Model:FindFirstChildWhichIsA("Humanoid"). Also next time format your question properly because it matters.