basic news site for web+iOS+android with native languages & backend stack

Hello
Looking for the create a platform that works for all platforms which includes
-Login/Sign up
-Notifications
-Admin panel
-Images,slides,Videos
-Admob
-Individual selected theme
-Open and free news api for 1st release
languages;
- Android - Java/Kotlin
- iOS - Swift
- Web - any
- Backend (firebase/aws/mongoDB depends)