Download and open the latest version of the Dropbox mobile app.
Tap I'm Already a Dropbox User.
Enter your email address but leave the password field blank. Tap Sign In to Dropbox.
If you haven't signed in to your company's page on your device, a browser window will open up and prompt you to do so. Enter your email address, work password. If you've already signed in on your device, you'll skip this step.
You'll be sent to a page in your browser that requests your approval for the app to use single sign-on. Tap Allow.
In the mobile app, follow the rest of the app setup process as normal to finish linking your device to your Dropbox account.