By default, Express doesn't parse JSON passed in the request body. In fact, the request body is seen as null by Express.
We need to add middleware to allow Express to be able to access the information passed in. In the past, we've had to lean on other libraries such as body-parser. As of version 4.17, Express now comes bundled with it's own JSON middleware.
We will use that middleware in this lesson, build some logic and send a response back to our client.