lag

Hi, there has been uncontrollable lag on my server? All the mods work fine with no lag on a normal singleplayer world but when it comes to aternos it lags so much and it's hard to build and walk without lagback, chat delay, etc.

Is there anyone who can help me resolve the issue? Or is it just better off to just deal with the lag. *please notify if I need to provide anything, a log or anything*