A single password is not safe enough. That is why the two-factor authentication (2FA) is introduced.

Read how to set up 2FA with SMS code.
Read how to set up 2FA with the Chrome Authenticator extension.
Read how to set up 2FA using the Google Authenticator app on your mobile.
Read how to set up 2FA using the Microsoft Authenticator app on your mobile.
Read how to set up 2FA for a shared account.

You can simplify logging in. Select the box Trust this device and skip the extra factor next time I login while logging in. This means you only have to use log in with the 2FA once every 30 days. Only select this option on a personal computer.

Due to security reasons, the 2FA is mandatory.