I recently heard about such a new way of earning money as staking Aptos and got interested in it. Maybe someone already has experience with this way of investing? Can you please tell me how profitable it is? And how does it work?

It's very simple: staking uses the PoS algorithm, which is one of the methods of protecting the blockchain from hacking and unreliable data. That is, when users choose a blockchain with this algorithm and store coins, such as Aptos, in their wallets, they get a reward, it incentivizes the participants of the system to participate in the process of staking and thus keep the blockchain in working order. By the way, you can try staking yourself - https://xbanking.org/.