ok, i'm not surprised i was wrong about the player, i've only ever sent in opposite direction. getSender is there and i should have checked instead of posting blindly...
but how would he know the block location without including it in the message?
Sorry I can't find any premade tutorials for 1.17 at the moment. It really depends on the version of forge you are using. But here's the rundown:
You want to look at classes such as BeaconBlock, or ChestBlock, BeaconMenu, etc. to help you with these steps, but you need to do the following:
1. Make a block extending BaseEntityBlock (BeaconBlock)
2. Make a block entity for it (BeaconBlockEntity)
3. Make a menu for it (BeaconMenu)
4. Make a screen for it (BeaconScreen)
I know it's a little complex, but I'm sure you can find tutorials online, or if someone else comes in to help.