android developer needed to fix an app with some issues

Hello
i have an android app integrated with facebook audience network and must be transfered to bidding

some issues need to be fixed

1-App crashes alot
2- sdk's needs to be updated
3- i'm integrated with Facebook audience network and they have changed from waterfall to bidding and the ads stopped on the app
4- a method must be added on the gradle file its ((implementation 'com.google.ads.mediation:facebook:6.5.1.1'))
5- the most issue must be fixed is the ads must run again on the app


please only android developers must bid