- Go to Dropbox.com and login to your Dropbox account. 
- At the top-right of the page, where it shows your name, click the Down arrow and select “Settings”. 
- Click the “Security” tab and scroll down all the way to the bottom. You should see “Two Step Verification” field under your Account Information. Click the “Change” link. 
- On the popup screen, click “Get Started”. 
- Next, you can choose between two verification methods – text message or mobile authentication. 
If you select the mobile app, it will show you a barcode where you have to scan to add in the key to the Authenticator app in Android/iOS (the one you use for Google Authentication). You will then be asked to enter the code for the first verification. 6. Lastly, it will show up a string of text and number that you need to write down and store it in a safe way. In the event that you lose your phone or the 2-step verification fail, this emergency code is required to disable the 2-step verification.
That’s it.