How Do I Make An R15 Starter Character That Can Have Custom Animations?

Help and Feedback Scripting Support
#1

I’ve been trying to make a starter character that can walk and run in R15. It can already run normally, but I want to change the animation to one of the roblox catalog animations. e.g The Heavy Run 3236849826. Please help if you know how to do it

#2

Replace the animation by using the HummanoidDescription object.

#3 
local Game = game
local Players = Game:GetService("Players")

local function OnPlayerAdded(Player)
	local function OnCharacterAdded(Character)
		if not Player:HasAppearanceLoaded() then Player.CharacterAppearanceLoaded:Wait() end
		local Humanoid = Character:FindFirstChildOfClass("Humanoid")
		if not Humanoid then return end
		local HumanoidDescription = Humanoid:GetAppliedDescription()
		HumanoidDescription.RunAnimation = 3236849826
		task.wait()
		Humanoid:ApplyDescription(HumanoidDescription)
	end
	Player.CharacterAdded:Connect(OnCharacterAdded)
end
Players.PlayerAdded:Connect(OnPlayerAdded)