title: react native login username not find
body: <p>can someone help me, i dont what will i do. this code always error if i setting the username and password. i'am a newbie, this my first work build app with react native</p>
  
  <pre><code>export default class Login extends Component {
  
     constructor(props) {
      super(props);
      this.state = {
       username: '', 
       password: ''};
    }
  
  
    async loginAjax() {
      try {
        let response = await fetch('http://panel.erzap.com/web_services/login_json/new.json', {
          method: 'POST',
          headers: {
            'Accept': 'application/json',
            'Content-Type': 'application/json',
          },
          body: JSON.stringify({
            erzap: {
              username: this.state.username,
              password: this.state.password,
              }
          })
        });
        let responseJson = await response.json();
        Alert.alert(responseJson.notice);
      } catch(error) {
        Alert.alert(error);
        console.error(error);
      }
    }
  </code></pre>
  
  
  
  <p><a href="https://i.stack.imgur.com/UPAUP.jpg" rel="nofollow noreferrer">enter image description here</a></p>