My animation not working, while other one does?

I have a roll animation that plays on key pressed. It doesn't work, but I put in my other simple hand movement animation, and it worked. What am I doing wrong? Here is my script: server side

local rs = game:GetService("ReplicatedStorage")

local function onPunchFired(plr)
    local char = game.Workspace:FindFirstChild(plr.Name)
    print(char.Name)
    local humanoid = char.Humanoid
    local animation = Instance.new("Animation")

    animation.AnimationId = "rbxassetid://2751075919"
    local animTrack = humanoid:LoadAnimation(animation)
    animTrack:Play()

end

rs.punchEvent.OnServerEvent:Connect(onPunchFired)

it prints the player name with no error.