Add sub-collection inside another Collection in Flutter Firebase

If you are looking for how to create subcollection (nested collection) and store data in this subcollection this tutorial is for you.
keyword:
#subcollectioninfirebase
#flutter
#nestedcollection
#subcollection
#fluttertutorialforbeginners
#fluttertutorial

[@devs-ys6fu]

🔥solved!! thank U