body parser package is deprecated. If you are using latest version of express you don't have to install body-parser package.

You can directly use

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

If you facing 'bodyParser' is deprecated.

Just do

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

Note: If you are using 4.16.0 or later express version.

Body parser is now added to Express. You can use it like the following:

app.use(express.json());

You can add this middleware to the code which will then be able to use json methods.

Don't use body-parser

Body parsing is now builtin with express So, simply do

app.use(express.json()) //For JSON requests
app.use(express.urlencoded({extended: true}));

directly from express

You can uninstall body-parser using npm uninstall body-parser

Then you can get the POST content of the request using req.body

app.post("/yourpath", (req, res)=>{

    var postData = req.body;

    //Or like this, for string JSON body

    var postData = JSON.parse(req.body);
});