How to create a timer that stops and resets itself when a value = 0?

How can I create a timer that stops when a value = 0?

I want to make a timer where when a value = 0 then it resets the timer. Essentially when the value = 1 it starts the timer and counts down from 20 to 0 but if the value = 0 then it stops and resets the timer and doesn't count down. How can I go about doing this?

Here's something that might help:

(Script)

value.Changed:Connect(function()
	if value.Value == 1 then
		for i = 20,0,-1 do
			timer.Value = i
		end
	elseif value.Value == 0 then
		timer.Value = 20
	end
end)

I don't know how the timer is set up, but right here I made it a value, which should be the case for a timer working in a server script and make a local script update the text of the timer.

I hope this helped!

Well I figured it out myself:

Script:

for i = 20,0,-1 do
			if value.Value >= 1 then
					wait (1)
				timer.Value = i
				
			elseif value == 0 then
				timer.Value = 20
			end
				end