Lock Chest Command (No Mod!) by xxmoonygamerxx

1. Place Command Block under          Chest.
2. Put a lever connected to the           Command block or change it to      Redstone: Unconditional. Insert      The command below.
3. Name an item the same name as    The key. Any item will do. Tripwire Hooks and Levers are suggested.
4. I don’t own this command. This is areference. 
5. This may not work on 1.12