message: path is required
I believe your problem might be that body-parser is not configured.
Try npm installing body-parser, then import it at the top of your main server file:
bodyParser = require('body-parser');
Finally, configure it for use. This will allow you to use x-www-form-urlencoded:
// Setting up basic middleware for all Express requestsapp.use(bodyParser.urlencoded({ extended: false })); // Parses urlencoded bodiesapp.use(bodyParser.json()); // Send JSON responses
Check your req.body.author, req.body.rating, req.body.reviewTextThey must be coming as empty string