Customisations in flutter apps

I am looking for a Flutter developer who can help me with customizations in my app. Specifically, I need improvements in functionality.

Project: https://codecanyon.net/item/supermarket-grocery-store-android-apps-complete-package-with-3-apps/22083396

Customisations:
1. Introduce subscription module in app for milk deliveries which can be paused resumed for vacations. - Recurring payments

2. Introduce delivery system in which we can take pre orders and do delivery twice a week like Wednesday and Friday and it can be adjusted from admin panel, user can select the day of delivery with available time slots while checkout. - Currently it has only time slots for each day in week.

Requirements:
- Strong experience in Flutter development
- Proficiency in implementing custom functionalities in Flutter apps
- Ability to work with a detailed list of functionalities provided by me

Timeline:
- There is no specific deadline for the completion of these customizations, but the sooner the better.

If you are a skilled Flutter developer with a strong understanding of customizations and functionality enhancements, please reach out to discuss the project further.

The lowest quotes gets the deal