How to update wait timer with a gamepass?

I'm having a problem with my code. I have it coded to where it will randomly pick a number from 5 to 2700 and then wait that many seconds. I have a game pass where a player can buy it and reduce the time via a intvalue. Only problem is since the code has already fired the wait timer it won't update the time being reduced. But I still need the timer to count down even before the person buys the game pass.

local fire = script.Parent.Fire
local bool = script.Parent.Fire1
local chance = script.Parent.Chance
while true do
    bool.Value = false

    wait(math.random(5,chance.Value))
    bool.Value = true

    wait(120)

    bool.Value = false
end