
This will recover your key, unlock the drive, and let you reset your account password.

Now, depending on your choice in setting up FileVault, you will see one of several options (the text may vary in Mojave and earlier releases of macOS): In Mojave and earlier, you have to enter your password incorrectly three times before a prompt appears.Some lengthy text appears that starts “If you forgot your password you can…” In Catalina and later, a password field appears with a question mark (?) at the far right.Next, at the login screen click your account icon:

The question mark is your key to unlocking a Mac that’s protected by FileVault.
