Develop mobile app to manage food websites

I want to build Flutter mobile App (ios and android) to manage food online ordering website. The app will act like admin panel for website. I already have few website which already up and running and each website has its own cpanel and its own database and all websites are on same server I want to build app so when it runs it asks for username and password for specific website and when you login I want to be able to view list of orders, opening times, view order details, view reports by date, see list of customers, change menu.....etc. please see the attached images for similar manager app which I want the same.