The update contains:
1) Support only 1.21
2) Changing the limitations of the demo version from the system: “only rivers” to “200 blocks in the spawn radius”
Now users will have access to all content, but within a limited radius. Previously, the demo version only worked on rivers.
3) Fixed a bug with putting a large fish on the head.
4) The plugin also contains code for a future update with GUI and skills

Due to many changes in version 1.21, a lot had to be rewritten. If you need a version less than 1.21, please let me know.
The update contains part of the code with a graphical interface and skill leveling. But they have not yet been completed and are not available. If you have suggestions on this topic, write!