iOS Wellness app update

I own an iOS app for iPad that was developed back in 2013/2014 by a third party. It is a wellness based app. The app was available for a short period of time on the App Store but was then parked till now. I am looking for someone to update whatever needs updating - iOS and device etc so that I can run the app on current iPad devices and be ready to submit to App Store. I have all the files and code etc. Thanks
Kieran