Hello.
Today, when logging into the wallet, I received a message about an outgoing transaction dated 12/03/2023. As a result, my balance was reset to zero. What should I do? Can I do anything to return the money?
(Program version 4.3.3 at the time of entry)
I will start by telling that the bitcoins never stay in the wallet. The wallet only handles the keys.
So there's an extremely good chance that somebody got access to your wallet seed, restored (basically obtained a copy of) your wallet and then spent your coins.
Since bitcoin transactions are irreversible, if the transaction is confirmed you cannot get your money back.
What you can do? Try to find out how did your seed got stolen - is your system compromised, or did you save the seed in mail, or cloud? (If system is compromised you may lose more than only the bitcoins). As the others said: learn how bitcoin works, learn to keep your money safer, consider buying a hardware wallet for your coins.