Recreating flappybird in P5JS. (original i know). I dont know exactly how i am supposed to spawn the “pipes” at different heights

So i have a small assignment of recreating flappy bird, where the player has 10 lives and loses one every time they touch the “pipes”. Im essentially done but would like to make it so the openings of the pipes are located at different y values sort of like this. How would i exactly go about doing that.

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