Please click this link and follow the guide. If you are using a server host such as Bisect, you may be limited in your options and instead have a checkbox to use Aikar's Flags, which will also work:
https://github.com/etil2jz/etil-minecraft-flags
If you can not launch your server/game after using these flags, then remove the word java from the start. Also, make sure you are using Java 18 on 1.18.2 / 1.19.2 and Java 11 on 1.16.5. These should be downloaded from Adoptium's website.
If lag persists, do the following command ingame:
/spark profiler start --only-ticks-over 50
Then, send the link in this channel.














