How do i detect if a key is being held?

How would i detect if a key is being help? For example : lets say you hold the E button to charge something to make it bigger and if you let go at any moment it fires at that moment. Like if you hold it for the max seconds you get a bigger ki blast, and if you don't you get different sized blast's depending on how long you held the E button.

I was thinking of doing this :

local UIS = game:GetService("UserInputService")
keyHeld = game.workspace.Part.Size
keyCharge = false

UIS.InputBegan:Connect(function(Input)
local KeyCode = Input.KeyCode

if KeyCode == Enum.KeyCode.G and keyCharge == false then
keyCharge = true
print('started')
end
end)

UIS.InputEnded:Connect(function(Input)
    local KeyCode = Input.KeyCode

    if KeyCode == Enum.KeyCode.G and keyCharge == true then
        keyCharge = false
        print('ended')
    end
end)

while keyCharge == true do
wait(0.1)
keyHeld.Size = keyHeld.Size +Vector3.new(1, 1, 1)
--game.workspace.Part.Size = game. workspace.Part.Size +Vector3.new(1, 1, 1)
end