I want to active all alarms at once?

I would like to active all alarms for my game, they have a toggle value and a script. I would like to active all of copies of it, just change toggle value to true, I tryed denestats but i don't know how it works i am a begginer

If they're in the Workspace you can just iterate through all the children in the Workspace:

for _,v in pairs(workspace:GetChildren()) do
	alarm.Active.Value = true
end

You will have to use workspace:GetDescendants() instead if some/all are not direct descendants (i.e some are in a model) of the workspace. If your game is decently sized it WILL lag.

I recommend you put them into a folder and do folder:GetChildren() instead.