why is 'body' empty in nodejs express post request?
As you are using POSTMAN to be able to access request body via req.body when you are using the buildin express.json middleware you will have to ensure that are send the request Body using RAW type and set the type of the body as JSON like in the image shown bellow
If the body type is set to something else (Text, JavScript, HTML, XML) You'll still getting an empty body. Only when it's set as JSON you will get req.body filled with data which you sent as part of you request body