he was making the ranks save into a mysql database and then put into the users.txt whenever that person joined
ill show u
--[[
https://ulyssesmod.net/docs/index/Hooks.html                         for commandcalled maybe
https://github.com/FredyH/MySQLOO/blob/master/lua/mysqloolib.lua     mysqloo info
]]

require ("mysqloo")
--file.Delete("data/ulib/users.txt") gonna uncomment this when verified working

local DB_HOST = ""
local DB_PORT = 3306
local DB_NAME = ""
local DB_USERNAME = ""
local DB_PASSWORD = ""

database = mysqloo.connect(DB_HOST, DB_USERNAME, DB_PASSWORD, DB_NAME, DB_PORT)
database:connect()

function database.onConnected( db )
    database:query("CREATE TABLE ulibusrs (steamid VARCHAR(33) PRIMARY KEY NOT NULL, pname VARCHAR(33) NOT NULL, pgroup VARCHAR(33) NOT NULL)" )
end

hook.Add("PlayerAuthed", "ULIBsqlusers", function(ply,steamid,_)
    local linfo = database:query("SELECT ulibusrs.pgroup FROM ulibusrs WHERE ulibusrs.steamid = '"..steamid.."'")
    if (type(linfo) == "table") then
        if type((linfo["group"]) == "table") then
            --local userInfo = ULib.ucl.authed[ ply ]
            ULib.ucl.addUser( steamidxxxxxxxxx, {}--[[userInfo.allow]], {}--[[userInfo.deny]], linfo[1]["group"] )
            return
        end
    end
    database:query("INSERT INTO ulibusrs(steamid,pname,pgroup) VALUES('"..steamid.."', '"..ply:Nick().."', 'user')")
end)

hook.Add("ULibUserGroupChange", "updatesqlusr", function(id,_,_,group,_)
    database:query("UPDATE ulibusrs SET ulibusrs.pgroup = '"..group.."' WHERE ulibusrs.steamid = '"..id.."'")
end)

hook.Add("ULibPlayerNameChanged", "updatesqlusr", function(ply,_,newname)
    database:query("UPDATE ulibusrs SET ulibusrs.pname = '"..newname.."' WHERE ulibusrs.steamid = '"..ply:SteamID().."'")
end)