using postman extension

 For api testing, you can install chrome/edge postman plugin.

Tabbed Postman - REST Client

Once you install it, you can test it using extensions--tabbed postman.

while sending a api request, you need to set the header data as below.

Content-Type: application/json

By default it should be set, if not add this pair in header section manually.

Add this in your index.js of node project based on your rquirement.

app.use(express.urlencoded({ extended: true }));

If it is provided, then in the postman, you need to keep value as false above for raw testing with application/json header