[Fixed Like 2 days ago] Keeps saying Attempt to index local (a nil value) help please?

First, tab your code correctly. That has solved the last two problems I've read, you should get in the habit.

local po = game.Players.LocalPlayer;
--Get the player
local Mouse = po:GetMouse();
--Get the mouse

Mouse.KeyDown:connect(function(Key)
    --Activated the KeyDown function with GetMouse
    if (Key:lower() == "k") then
        -- Pick key to use
        local po = game.Players.LocalPlayer
        local Power = Instance.new("Animation")
        -- name before the "=" neoNob
        Power.AnimationId = "220836646"--Same here neoN0b
        local animTrack = po.Character.Humanoid:LoadAnimation(Power)
        -- name in parentases, neoN0b
        animTrack:Play()--Play pls
    end
end)

Now the error is telling you that po is a nil value. That means it's not a thing.

po = game.Players.LocalPlayer so po is supposed to be the LocalPlayer. But there isn't a LocalPlayer.

That probably means this is a Script object instead of a LocalScript. Script objects can't use LocalPlayer.

First off, GetMouse is depricated. Don't use it anymore. You have to use UserInputService or ContextActionService. I prefer UserInputService.

local UIService = game:GetService("UserInputService")

UIService.InputBegan:connect(function(input)
    if input.KeyCode = Enum.KeyCode.K then
        local po = game.Players.LocalPlayer
        local Power = Instance.new("Animation")
        Power.AnimationId = "220836646"
        local animTrack = po.Character.Humanoid:LoadAnimation(Power)
        animTrack:Play()
    end
end)

UserInputService uses InputObjects. These can give you all the information based on mouse position, keycode, and other things. View the API of UserInputService here and InputObjects here.

Lol turns out I didnt type the whole animation ID Surprised you guys didnt see that.