Unique Username

41

Although I am able to make changes in my isNewUser feild.

42

I canā€™t add information in my User databse.
Here is my app in editor mode

Over here I canā€™t add the username that is in the popup box. Please Help

43

In this question, what I found really important is, do not forget to set the constraints while searching for any databaseā€™s field.