Freelancing Mobile App developer

I have a mobile app that has its front-end and database ready, the framework is done in Flutter using mySQL database. I have three main users in my app, service seeker, service provider and admin. I want someone to help my developer to finish the backend functionalities of the app, and these are the remaining functionalities -written as stories-:
1.1- I want backend for admin for all CRUD operations
1- service seeker wants to rate service provider
2- Service seeker wants to pay
3- service provider wants to view all services
4- service provider wants to send application for services
5- service provider wants to view My Services (applied, current and done)
6- service provider wants to accept hire for a service
7- service provider want to enter their bank account number to be paid
8- service provider wants to be notified if they are messaged
9- Service seeker wants to post a service
10- Service seeker wants to hire service provider
11- Service seeker wants to message service provider
12- Service seeker want to invite service providers
13- Service provider wants to view his rating
14- Service seeker wants to switch to service provider
15- service provider wants to switch to seeker
16- Service seeker wants to report abusive content
Please contact me if you are willing to help my developer in building this app.