Xamarin expert required

We have an ongoing application in Xamarin and the backend is in Laravel it's almost completed and all third party APIs and Payment gateway integrated but we are getting error in the following points-

Facebook login (Integrated testing error)
Fingerprint auth error
Password check button
Google pay (integrated testing error)
Apple pay (integrated testing error)
Login/Signup issues sometimes.
Order history
FAQ
Privacy policy
Uploading build on Playstore and Appstore
Scanner process
Application Name/Logo/Content

All the services are working, we are looking for individual or any company who will finish this work in 4 days including weekend.