how to specify header application/json in axios code example

Example 1: axios post with header

// Send a POST request
axios({
  method: 'post',
  url: '/user/12345',
  data: {
    firstName: 'Fred',
    lastName: 'Flintstone'
  },
  headers: {'Authorization': 'Bearer ...'}
});

Example 2: making axios call with headers

axios.post('url', {"body":data}, {
    headers: {
    'Content-Type': 'application/json'
    }
  }
)