It happens. You left your mobile device at home, and now you can't use your phone to verify who you are. Maybe you previously added an alternative method to sign in to your account, such as through your office phone. If so, you can use this alternative method now. If you never added an alternative verification method, you can contact your organization's Help desk for assistance.
Sign in to your account but select the Sign in another way link on the Two-factor verification page.
Change sign in verification method
If you don't see the Sign in another way link, it means that you haven't set up any other verification methods. You'll have to contact your administrator for help signing into your account.
Choose your alternative verification method, and continue with the two-step verification process.
Regards,
Rachel Gomez