Make sure to have two databases ready and name them accordingly
The names of my DBs are test_app and test_main
test_app is the first app where registration happens and test_main is in our case "crossplatform" database.
The collection names in my case are:
test_app: users
test_main: testmainusers
Use postman to send post request at this link: http://localhost:3000/api/user/create-user
Run using the following commands
npm install
node app.js