Fix One-Time Password (Otp) Generation in Existing Android Mobile App

I have a mobile application that is currently installed on my phone but is no longer available on Google Play. The app itself is not blocked by Google; however, a critical functionality has ceased to work properly: it no longer generates One-Time Passwords (OTPs). I am seeking a skilled freelancer to diagnose and resolve this issue. The project involves investigating the existing application, identifying the root cause of the OTP generation failure, and implementing a solution to restore this essential feature. Experience with Android development, API integration, and debugging existing mobile applications is required to ensure the app can reliably generate OTPs once again.