Install, Customize & Modify of a CodeCanyon Script

I need the service of a competent freelancer to help customize & modify a Codecanyon script already installed on my server. The following services required are:
1. Help resolve Sign-up & Sign -in Authentication
2. Help resolve Map API Integration
3. Set Cash on delivery as the only payment system
4. Help upload product list
5. Help create Custom field for more categorizations
6. and help to setup all other script features.
NB: Please check the following link for more information
1. https://codecanyon.net/item/grocery-food-pharmacy-store-delivery-mobile-app-with-admin-panel/26409320?utm_source=codecanyon&utm_medium=profile&utm_content=profile-banner&utm_campaign=grocery-delivery-app#
2. https://codecanyon.net/item/delivery-boy-for-groceries-foods-pharmacies-stores-flutter-app/26615174
3. https://codecanyon.net/item/owner-vendor-for-groceries-foods-pharmacies-stores-flutter-app/28230759
4. https://codecanyon.net/item/customer-website-for-grocery-food-pharmacy-store-delivery-laravel-app/33465362