Signing into your @wisc.edu Google account
If you're like many other people you have a personal google account. It will be something like email@example.com.
Go to https://www.google.com
Click on your profile picture in the upper right and then click on "Add another account"
for the sign in email address, enter in either firstname.lastname@example.org and click "Next"
You should be prompted with a normal NetID authentication window which you can again enter your NetID and password followed by a Duo Mobile login.
Should you later need to toggle back and forth between your Google identities, you can click on your profile picture and click the alternate identity. (See the picture above.)