LevelAccessor level = player.getLevel();
level.destroyBlock(blockPos,false);

i need to destroy the block at xyz coordinates, the block is broken and put back

You need to make changes to the state of the world on the server.

If you do it on the client, it will be a ghost modification only that player can see.

Eventually, the server will resend the correct state and overwrite your changes.

https://forge.gemwire.uk/wiki/Sides

11 hours ago, warjort said:

You need to make changes to the state of the world on the server.

If you do it on the client, it will be a ghost modification only that player can see.

Eventually, the server will resend the correct state and overwrite your changes.

https://forge.gemwire.uk/wiki/Sides

 

Thanks for the answer, but I don't know how to do it. Please tell me how to do it

Edited April 20, 20232 yr by gnomuk

Your question in its current form will likely just be ignored, see:

https://forums.minecraftforge.net/topic/118559-solved1192-how-to-use-friendlybytebuf-reader-and-writer/#comment-521051

i dont know how break block on server side? I can break block on client side only. Please help me, warjort

Send us your entire code file, not just that small portion you posted. You are most likely telling the game to break a block on an event that only happens on the client side.