How to Stop the timer and Continue to the next Question?

I made a quiz where there is a timer, but I made a function that if you Answered the question before the timer that it should be able to skip to the next Question. It does all of that but it doesn't skip to the next question, instead, it continues to use the timer.

if on == true and TimerOn == true then
	for t = 20,0,-1 do 
		Countdown.Text = t
		TextBox.Changed:connect(function()
			if EnterStorage.Text == A3 then 
				Score.Value = Score.Value + 10
				EndTest.Value = EndTest.Value + 1
				Correction.Text = "Correct" wait(3)
				if Correction.Text == "Correct" then 
					Questions = math.random(1,3)
				end
			end 
		end)
	wait(1)
	end
end

Do I need to show more of the script for you guys to understand?