APK for Android 6, iOS 9 or 12

I have an LG K210 (X power from Canada) running Android 6, Asus Zenfone running Android 6, iPhone 6 running Android 12 and iPad 2 running iOS 9.

Can any of these install Duo Mobile from an APK or other?

I need the app for school. Georgia Tech.

Hi @Nobu_Taka, welcome to the Duo Community!
We support Android 12, but we don’t support the other OS versions that you listed. You can find more information on currently-supported OS versions in our documentation: https://guide.duo.com/
If you’re using this app for school, try contacting your school’s student help desk for IT for more support on using Duo Mobile on these devices to access your school’s resources.
Hope this helps!