Editing some stuff in helptext plugin

Hi,
So i try yestarady to take the plugin "helptext" and make it to "helptextadmin" and I succedded to make another plugin like this just with other command and config, but i don't know where to put the code that only allow to admins to type the command.

this is the code:

Code:

function PLUGIN:SendHelpText(player)
    if player:IsAdmin() then
        player:ChatMessage("admin helptext")
    end
    player:ChatMessage("normal helptext")
end

i want to put this code in the plugin and also make that when a regular player will type this command, it will type for him a text "you don't have premission".

and last thing, i saw this: Steam profiles to use for icons | Oxide
and i don't know where to put the code.

thank you for the help