Instructions

1. activate the addon on the world

2. Enable cheats

Now you're done with the basic settings and can enter the world. The add-on creates a player.json file and could cause bugs with other add-ons. Furthermore, the add-on doesn't require any future updates and works in every version.

command

Execute the command /event entity name kill:PermaKill. This will kick you from the world, and if you rejoin the world, you'll be permanently dead. Instead of @s or name you can use any other name

Result

This is what it looks like when you're permanently dead. There's no way to respawn unless you delete your player data. All you can do is write in chat or rotate the camera.

Fun fact: this project was created due to an error in another project