how to integration vpn mva and owa

I think you need to find a competent partner and procure professional services for architecture design and potential assistance with implementation.

I agree if whisperer if you really haven't done something like this before. Reach out to your F5 partner or reseller if you have one.

Else you can search for OWA DUO F5 documents, there are some suggestions here: https://community.f5.com/t5/technical-forum/two-factor-authentication-for-owa-with-f5-apm-and-duo/td-p/241683

Beyond that DUO seems to do this also with an own plugin: https://duo.com/docs/owa