These steps are for macOS Catalina or later. The steps for macOS Mojave or earlier are different. If you're not sure which macOS you're using, try these steps first.

The login window appears after you turn on, restart, or log out of your Mac. It's not the same as the window you might see when waking your Mac from sleep or stopping the screen saver, though it uses the same password.
After making sure that you're at the login window, enter any password up to three times until you see one of the password-reset options below.
After you enter a password up to three times, your Mac should show one of these password-reset options.

