"DiscordSRV v13.3" has registered a listener for org.bukkit.event.player.PlayerAchievementAwardedEvent on method "public void github.scarsz.discordsrv.listeners.PlayerAchievementsListener.PlayerAchievementAwardedEvent(org.bukkit.event.player.PlayerAchievementAwardedEvent)", but the event is Deprecated. "Server performance will be affected"; please notify the authors [Scarsz & Androkai].

This was in my console

It's because achievements will be removed in the future of Minecraft and DiscordSRV is working with them. We already fixed this in our development branch. Nevertheless, thank you for the report. 👍