3-Flutter, Requests management ( read no.4 in description )

Note: it's cross platform app using mysql DB. 1- 3 type of users A- the admin group can ( create users, add funds, edit and delete functionality) B - The buyer group ( can check requests, receive notifications, pay, check balance ) C- 3rd party ( can add notes to requests) D- warehouse group ( can send requests, confirm payment). 2- The app is about creating selling items from warehouse, then the invoice come to the user, after he pay them, the third party make sure it's correct item . all this monitored by the admin group who can also add users and fund. 3- This is on going project so we will keep adding features to it. 4- I'm looking for a long term developer, a regular customer is better than one time job so please lower your bid as possible. 5- Report needed ( monthly , per user, between two duration) 6- nice design