You should receive a notification on all connected devices. If you have multiple devices linked to your Dropbox account, click Having trouble getting a code? in the window that appears when you try to sign in, and then click Send me a notification. Then, find that phone or contact the person that has it, and follow the prompts from there. If you did, or you think you might have, click Having trouble getting a code? in the window that appears when you try to sign in, and then click Text my backup phone. When you set up your Dropbox account, you may have added a backup phone number that can receive texts.

If you still have your backup code, click Having trouble getting a code? in the window that appears when you try to sign in, and then click Enter the emergency backup code and type in your code. If you did, you were told to save it for your records. You may have set an emergency backup code when you set up your Dropbox account. Try the following methods before contacting Dropbox support. If you lost your phone or got a new phone number and no longer have access to your old phone number, there are several alternative ways to receive a two-step verification code. They will be able to reset your two-step verification settings. Note: If you’re on a Dropbox Business team and are having issues signing in with two-step verification, contact your team’s admin for assistance.

Dropbox security