Locks Player Guide
The lock recipe is an Iron Ingot placed above an Iron Block. This will give you a lock item.
Once you have a lock item, right-click on the block you wish to lock with it. You will be given a key, and every block adjacent to the block you have locked will only be able to be interacted with by players who hold the key in their inventory or keyring.
You can place keys on your keyring by using the /keyring command. This command opens an inventory which may be used to store keys. Keys placed on the keyring may be used the same as keys in your inventory.
If you wish to unlock a block, use the /unlock command while you have the key in your inventory. The next block you interact with, if locked, will unlock, consume its key, and give you back the lock used.
If a player wishes to get a duplicate of a key, you can use the /getkey command, before interacting with the block you wish to get a key for. This also works if you need access to a container or door which is locked. Keep in mind if duplicate keys have been created, they will not be consumed when /unlock is used.