Custom app and backend

Hello
We have this app:
- https://codecanyon.net/item/gym-master-gym-management-system/18801887
- https://codecanyon.net/item/gym-master-mobile-app-for-iphone/20253978
- https://codecanyon.net/item/gym-master-mobile-app-for-android/19825196

But we need to custom Backend and app.

About "Backend":
We need to add those menu and functionnality
- All menus https://prnt.sc/1756ubs from this code https://codecanyon.net/item/gofit-complete-react-native-fitness-app-admin-panel/22286497

About "Apps" (ios and Android):
- Here https://prnt.sc/175779k and here https://prnt.sc/1757cl3 add the new menus from here https://prnt.sc/1757lc8
- Instead this https://prnt.sc/1750u52 should be like that https://prnt.sc/1751pma then https://prnt.sc/1751tv4 then https://prnt.sc/1751yks from this code https://codecanyon.net/item/fitness-7-minute-workout-is-android-application/25046532
- But here https://prnt.sc/17524sq need to use this https://prnt.sc/1752ku7
- Use this https://prnt.sc/1752sda

Please check all and give me a real quote.
About all source I will provide you.

Thanks