How would I make an admin loader?

Loaders are made using ModuleScripts, and they are generally more secure than having a script in-game.

Here's how to make one:

Create your ModuleScript (name it "MainModule", I also recommend you parent it to ServerStorage, as I have encountered some errors when it wasn't). It can also have children inside it, they get saved with the model.

Test your ModuleScript. If it works, upload it to ROBLOX (don't worry, it can be updated if you make some errors in your code).

Then, require it using it's ID. It will error if you do not own it and if it isn't free.

Example: (Edited)

MainModule (AssetId = 12345678)

local module = {}
local args
local admins

game.Players.PlayerAdded:connect(function(p)
    repeat wait() until args  and admins
    if admins[p.Name] or admins[p.UserId] then
        p.Chatted:connect(function(msg,rec)
            -- player stuff here
        end)
    end
end)

function module:setup(arguments)
    args = arguments
    admins = args.admins
    print("Fun commands " ..("enabled" and args.funCommands == true) or ("disabled" and args.funCommands == false).."!")
end

return module

Script

local args = {}
----------------

args.admins = {}
args.funCommands = true
-- etc.

----------------

local module = require(12345678)
module:setup(args)

There you go, your loader is done. Note that requiring using an ID doesn't work in LocalScripts.

Hope I helped!

~TDP