Learning Firebase series:
you can sign up your account with the following link.
Create your first project
Set up the project
Enter into the Dashboard
just click next step
Choose the location of Cloud Firestore
In this part, we have to change some default setting:
We change the database type to Realtime Database and modified the rule. So that the database can be read&write. Finally we have to click the depoly button to make sure everything is saved.