Can anyone help find out the cause of server lag? [java]

My paper server has been lagging and timing out players a lot recently (maybe since updating to 1.21.10, not sure). Can anyone help find what's causing the lag and how to fix it? (Also server is in offline mode as we have players from China and other mc-restricted areas who can't join without offline mode).

https://spark.lucko.me/uZXEnRFmyc