error: cannot find symbol

Help faced with this problem even if there is no item writes about this error what to do?

> Configure project : 
Fabric Loom: 1.0.17 
Not publishing sources jar as it was not found. Use java.withSourcesJar() to fix. 
> Task :compileJava 
C:\Users\Baraban4ik\MCreatorWorkspaces\leveling\src\main\java\net\mcreator\leveling\LevelingMod.java:32: error: cannot find symbol 
         if (handler.getPlayer().getExtraCustomData().getCompound("PlayerPersisted").isEmpty()) { 
                                ^ 
  symbol:   method getExtraCustomData() 
  location: class ServerPlayer 
C:\Users\Baraban4ik\MCreatorWorkspaces\leveling\src\main\java\net\mcreator\leveling\LevelingMod.java:33: error: cannot find symbol 
            handler.getPlayer().getExtraCustomData().put("PlayerPersisted", new CompoundTag()); 
                               ^ 
  symbol:   method getExtraCustomData() 
  location: class ServerPlayer 
C:\Users\Baraban4ik\MCreatorWorkspaces\leveling\src\main\java\net\mcreator\leveling\LevelingMod.java:35: error: cannot find symbol 
         LevelingMod.LOGGER.info(handler.getPlayer().getExtraCustomData()); 
                                                    ^ 
  symbol:   method getExtraCustomData() 
  location: class ServerPlayer 
3 errors