Reading JSON request values in Node.js

I have a web service written in node. I can successfully call this endpoint. Its setup like this:

myWebService: function(req, res) {
  console.log('Request received.');
  console.log(req);
}

I can successfully pass values via the header. However, I'm trying to figure out how to send raw JSON from Postman to the web service. In Postman, I've clicked the "Raw" tab, and selected JSON from the drop down list. I'm passing in some JSON that looks like this:

{
  v1:2,
  v2:'?',
  v3:'Some string of text',
  v4:['value 1', 'value 2'], 
  v5:{param1:"p1Value", param2:3 }
}

When the request from Postman is received, the request does not have the JSON in it. My endpoint is defined like this:

app.post('/api/myWebService', api.myWebService);

I know its working because 'Request received' is printing. In addition, I can see the request contents, including the header variables. I'm not sure why the JSON values aren't printing. If I enter key/value pairs into the x-www-form-urlencodded tab, I can see those values in the req.body variable. However, I would like to make this as clean as possible and send pure JSON if possible.

What am I doing wrong?