title: Value for title can not be cast from ReadablenativeMap to string
body: <p>Consider:</p>
  <pre><code>InsertDataToServer = () =&gt; {
    const { pinValue1 } = this.state;
    const { pinValue2 } = this.state;
    const { pinValue3 } = this.state;
    const { pinValue4 } = this.state;
    var String_3 = pinValue1.concat(&quot; &quot;, pinValue2);
    var String_4 = String_3.concat(&quot; &quot; , pinValue3);
    var String_5 = String_4.concat(&quot; &quot; , pinValue4);
  
    fetch(&quot;http://www.aonde.biz/mobile/doLogin.php&quot;, {
      method: &quot;POST&quot;,
      headers: {
        Accept: &quot;application/json&quot;,
        &quot;Content-Type&quot;: &quot;application/json&quot;
      },
      body: JSON.stringify({
        &quot;pin&quot;: 212,
      })
    })
      .then(response =&gt; response.json())
      .then(responseJson =&gt; {
        // Showing the response message coming from
        // the server after inserting records.
        Alert.alert(responseJson);
      })
      .catch(error =&gt; {
        console.error(error);
      });
  </code></pre>
  <p>In the above code, when I pass the &quot;pin&quot; parameter API, it shows this error:</p>
  <p><a href="https://i.stack.imgur.com/1Ilpq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1Ilpq.png" alt="In image show full error" /></a></p>
  <p>How can I resolve this issue?</p>