Help Me With Adding Animations To Key Events?

All you have to do, using UserInputService, is to bind a certain key, to process and handle the animation.

local player = game:GetService("Players").LocalPlayer
local uis = game:GetService("UserInputService")
local key = "E" -- key to bind

local animation = Instance.new("Animation")
animation.AnimationId = "animation asset id"
local character = player.Character or player.CharacterAdded:wait()

uis.InputBegan:connect(function(inputObject, processed)
    if not processed then
        if inputObject.KeyCode == Enum.KeyCode[key] then
            local humanoid = character.Humanoid

            if humanoid then
                local track = humanoid:LoadAnimation(animation)
                track:Play()
            end
        end
    end
end)

EDIT the second parameter to the InputBegan event, gameProcessedEvent, is a boolean value that is set to true if the game itself is processing the input... (ie: chatting).