Like previous services, Firebase Storage has an introductory step where it explains the need to secure data, as shown here:
The storage service is enabled with a default rule definition, where only authenticated requests can make write and read calls. This is enough for our application.
Again, for real-world applications, it is recommended to create the best rules you can do help to protect user-specific data: https://firebase.google.com/docs/storage/security.
After this introductory step, we can add Flutter-specific libraries and start the development step.