How can I play an animation on an NPC inside of a ViewportFrame?

I have an NPC inside of a ViewportFrame that I want to animate when you interact with it. The NPC is not anchored, and I've made sure my script works by using prints and I receive no errors.

Button.Activated:Connect(function()
    if not buttonActivated then
        local animation = Button.ViewportFrame.NPC.Humanoid:LoadAnimation(Button.Idle)
        animation:Play()
    end
end)