Test with jest and supertest leaves the posted request body undefined

I am testing an express API with jest and supertest. The goal is to test a post request with form parameters.

My test code is something like this:

test('create (name=John)', async () => {
    const res = await request(app)
    .post('/create')
    .type('form')
    .set('Authorization', 'secret')
    .send('name=John');
    expect(res.statusCode).toBe(400);
    expect(res.body).toMatchObject({
        "status": "error",
        "message": "Type is empty"
    });
})

The route is similar to this:

router.post(
    '/create', 
    oauth.authenticate(), 
    async function (req: express.Request, res: express.Response) {
        if (!req.body || !req.body.name) {
            return Base.badResponse(res, 400, 'Name is empty');
        }
        if (!req.body.type) {
            return Base.badResponse(res, 400, 'Type is empty');
        }

        // Logic here
    }
);

Im also using bodyParser to get the body formatted.

Testing with Postman is successful, so there is no general problem.

The request header for content-length have a value of 9 which represents the length of the parameter sent. The content-type is 'application/x-www-form-urlencoded' and correct.

My question is, why is request body still undefined wenn running the code with supertest?