Enable 2-step Authentication

If 2-step Authentication is enabled, then use the generated App password to login on the Regain Outlook PST Recovery software or disable the 2-step authentication.

If 2-step Authentication is enabled, then perform the below steps to disable the 2-step authentication:

1. Navigate to Security → Sign in with your Microsoft account.
2. Under the Two-step Verification section, choose Set up two-step verification to turn it ON, or choose Turn off two-step verification to turn it OFF.