I am trying to send new post via fetch, but every time I get these two errors (visible in an image).

Could you tell me why I am getting these errors?

 fetch('/posts', {
  method: 'POST',
  body: JSON.stringify({
      body: document.querySelector('#compose-body').value
  })
})
.then(response => response.json())
.then(result => {
    // Print result
    console.log(result);
});

Errors:

https://i.stack.imgur.com/7Lp2V.jpg