How to make a custom rig animate with a Humanoid?

I made a custom rig (It is an R15, holding a gun) and I animated it and then exported the animation to the website. Next, I imported the animation ID into an "animation" and tried using this script to play it on the custom rig:

wait(2)

s = script.Parent:LoadAnimation(script.Animation)
s:Play()

The script has the Animation as a child, and the script is a child of the Humanoid in the rig. This doesn't work. I also cannot use an AnimationController, because that requires no Humanoid. I need the Humanoid for the shirt/pants. Next, I tried a similar version of this script in the StarterPack in a LocalScript. Here it is:

wait(2)

local player = game.Players.LocalPlayer
local Mouse = player:GetMouse()

Mouse.KeyDown:connect(function(key)
if key == "r" then
s = player.Character.Humanoid:LoadAnimation(script.Animation)
s:Play()
end
end)

This one works fine, I set r to be pressed for the animation to play so I could personally test it multiple times. This works on my character, and doesn't work at all on the custom rig, what am I doing wrong?? I even built it on the rig, and my Character doesn't even have a gun. I'm totally confused.

Problem solved. Unanchor the HumanoidRootPart. So the reason I couldn't make it work is because when you're actually animating, you need the HumanoidRootPart anchored, and if you don't unanchor it, it won't work in an actual game.