1	Open firebase, select database on the left hand side.
2	Now on the right hand side, select [Realtime database] from the dropdown and change the rules to: { "rules": { ".read": true, ".write": true } }
3	node app.js
4	Test APIs using postman
5	make configurations at Header (KEY:Content-Type    VALUE:application/json)
6	(post) in Body the info : 
7	{
8	   “fname”:”aaaaa”,
9	   “lname”:”tttttttttt”,
10	   “email”:”[email protected]”
11	}