All the in-game items you can interact with — are NFTs. This means that each interaction with these items is a blockchain transaction that requires approval via the player's connected wallet.
During the first game session, you will be offered to get three in-game NFT items required for solving puzzles in the game world. In case one or more such items are available on a game scene, the initially chosen ones are considered duplicates. They will not be shown in your inventory. However, they do not disappear.
They are kept in your wallet, and you are free to use them in any way you want.
Hint: you can exchange your "duplicate" for any item you lack from other players.
Always remember the random choice of items at the very beginning in case you think you're stuck.
The random might not be on your side, so you may lack one of the items needed for passing through.