How do I activate Duo for my UMBC account?

This guide is for people who are brand new and are self-enrolling themselves into Duo, who just need to follow steps 1-4. For those who are automatically placed into Duo, refer to I've been enrolled in Duo, how do I register my device and use Duo?

Step-by-Step

Download and install the Duo Mobile application for your device from the app store (iPhone) or Google Play Store (Android). If you do not have a smartphone, skip this step.
Go to http://accounts.umbc.edu
Click on "Start Using Duo Two-Factor Authentication"
Click on "Activate Duo"
You should reach a page that says this:

If you need to deactivate duo, follow steps 1-3 again and click on Deactivate duo.

That's it! Duo is now active! Next, you need to enroll your device(s). You'll be prompted through the enrollment process the next time you authenticate to any UMBC resource.

You can find Duo enrollment help here.