how do i make a value permanent through servers, as in unlocking a power or something?

so im trying to make a shop and i need an item to permanently set a value to unlock a power, how exactly would i do this? here's the item's code so far:

Tool = script.Parent
local replicatedstorage = game:GetService("ReplicatedStorage")
local useevent = replicatedstorage.BuyDistraction
local cd = false

Tool.Activated:Connect(function()
	if cd == true then return end
	cd = true
	local plr = game.Players.LocalPlayer
	local char = plr.Character
	local hum = char.Humanoid
	useevent:FireServer()
end)

and here's the useevent

game.ReplicatedStorage.BuyDistraction.OnServerEvent:Connect(function(player)
	
end)

it is empty right now, as i do not know what to put in it. any help would be appreciated!

You may achieve data persistence via the use of DataStores. These are essentially a direct way to save data onto Roblox's servers, but you should be mindful of their limits. An implementation of them into your code would look like this:

local ReplicatedStorage = game:GetService("ReplicatedStorage")
local DataStoreService = game:GetService("DataStoreService") -- https://developer.roblox.com/en-us/api-reference/class/DataStoreService

local dataStore = DataStoreService:GetDataStore("DataStore_Name") -- Retrieves a DataStore with the given name.

ReplicatedStorage.BuyDistraction.OnServerEvent:Connect(function(Player)
	pcall(function() -- DataStores may often fail to save information if something goes wrong; pcall allows your script to keep executing if what's wrapped inside of pcall's function() throws an error. This is especially used in error handling: it returns two values, one being a boolean indicating the function's success, and the other being the error message that would've otherwise been printed to the output window.
		dataStore:SetAsync(Player.UserId, true) -- Sets the value of the DataStore key that is equal to the player's User ID to true (assuming all you need is to check whether they own the power via a boolean).
	end)
end)

This essentially saves the boolean true to the key [UserId] within the DataStore upon receiving OnServerEvent from the remote. To handle DataStore errors and actually retrieve data on join is another story. On a side note: sanity checks. You definitely need to add some way for the server to check the validity of what's being sent by the Client via BuyDistraction, or else anyone with a low level injector could exploit it.