Flutter app developer for readymade app corrections

I am looking for a Flutter app developer who can make specific corrections to my readymade app. The ideal candidate should have experience in UI/UX improvements and be able to integrate existing API endpoints. It is also important that the developer has an understanding of my specific design preferences. This project involves:
- Making UI/UX improvements to the app
- Integrating existing API endpoints
- Designing the app based on my specific preferences