Assuming there is a table named ClickDetectors that is a list of the ClickDetectorss, my first thought is to use Once on all the click events to increment a counter and then call some sort of function when that total matches the total ClickDetectors. Once will automatically disconnect the event after it is used, preventing multiple clicks on a single ClickDetector from incrementing the counter.
--Initialization code above with the ClickDetectors table
local PLFuel = game.Workspace.PLFuel --Update the reference to PLFuel. It should start at 0.
for _, ClickDetector in ClickDetectors do --pairs isn't required in Luau for iterating over a table. pairs(ClickDetectors) can be used for the same results.
PLFuel.Value += 1 --Increment the counter when the ClickDetector is clicked.
if PLFuel.Value ~= #ClickDetectors then return end --Only call the function if the counter has reached the total ClickDetectors.
print("All ClickDetectors clicked!")