Air Vent needs moved | Terry Love Plumbing Advice & Remodel DIY & Professional Forum

Hello,
The previous tub/shower combo that I ripped out allowed for the air vent to be above subfloor (as seen by pics). Of course , the new tub Delta Classic 400 won't allow this. Any suggestions on what to do with this vent.
This alcove is on 2nd floor of 2 story residential, Ohio.

Thank you.