Customize Flux pro Flutter Application

we have a Flux pro flutter application, wants to customize as following
1- login: we want to use a mobile number instead of email.
2- forget the password: in our backend, we are using OTP to confirm the mobile number for forgot password, then we direct the user to the forget password page, we need to do the same in the application, we can use a web view inside the app to redirect the user to change the password page on the remote website.
3- in the checkout, we have many customizations:
a: when we click on the search address button, we need a working map
b: customize the country list to read from the backend
c: we need to make sure payment is working and integrated with our backend for webhook.
4- we need to link some of the home screen widgets to different endpoints not only the default one.
5- in “my cart page” we need to remove the coupon list popup, we need the user to write the coupon not select one.
6- enable firebase and remote update to the app (its a flux builder feature)

App Link: https://codecanyon.net/item/fluxstore-the-universal-woocommerce-magento-opencart-mobile-app-by-flutter-framework/24020929