title: Fetch doesn't work in React Native ios
body: <p>I have login function in React Native where I try to fetch data. The function is as follows:</p>
  
  <pre><code>onLogin: function() {  //
          const self = this;
          self.setState({modalVisible: true, modalMessage: 'Signing in'});
          fetch('http://psa.autralis.com/manager/api/v1/obtain-auth-token/', {
              method: 'POST',
              headers: {
                  'Content-Type': 'application/json',
              },
              body: JSON.stringify({
                  username: self.state.username,
                  password: self.state.password,
              })
          })
              .then(response =&gt; response.json())
              .then(data =&gt; console.log(data))
              .catch((error) =&gt; {
                  console.warn(error);
              });
      },
  </code></pre>
  
  <p>But for some reason it doesn't work on <strong>ios</strong>. I get an error : </p>
  
  <p><a href="https://i.stack.imgur.com/BQBjZ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/BQBjZ.png" alt="enter image description here"></a></p>
  
  <p>On android it works, and I tested it with postman and there also works.</p>
  
  <p>Any idea?</p>