Recent versions of Bitcoin Core prefer "Descriptor" wallets for better security and compatibility. You can manually upgrade an old wallet.dat using these steps:
Shut down Bitcoin Core completely. Ensure the process is no longer running in your task manager. bitcoin core walletdat upd
Unlike a custodial exchange where you have a username/password, Bitcoin Core uses a Berkeley DB (BDB) database file named wallet.dat . This file is not a simple text file; it is a structured database containing: Recent versions of Bitcoin Core prefer "Descriptor" wallets