未处理的promise promise：SyntaxError：JSON解析错误：无法识别的令牌'<'

I am quite new in React Native. I have Login and Register pages which work well. After the user has logged in, the profile page should render Welcome + his name. I wrote a frontend and backend codes, but something doesn't work well.

Profile.js

export default class Profil extends React.Component {

constructor(props){
super(props);
this.state={name:''}
};

componentWillMount(){
  return this.getUser();
}

getUser(){
  return fetch('https://lifestormweb.000webhostapp.com/profile.php',{
  method:'GET',
  headers:{
          'Accept':'application/json',
          'Content-Type':'application/json',
      }
  })
  .then((response)=>response.json())
  .then((response) => this.setState({
  name: response.name})
  )
  }

  render() {
return (
  <View>
    <Header
      centerComponent={{ text: 'Profil', style: { color: '#FF0000', fontSize: 20, fontWeight: 'bold' } }}
      outerContainerStyles={{ backgroundColor: '#ffffff' }}
    />
    <Text>Willkommen {this.state.name}</Text>
  </View>
);
}

profile.php

<?php
$dbservername = "id6354774_users";
$dbusername = "id6354774_root";
$dbpassword = "*********";
$dbname = "localhost";

// Create connection
$conn = new mysqli($dbservername, $dbusername, $dbpassword, $dbname);
// Check connection
if ($conn->connect_error) {
  die("Connection failed: " . $conn->connect_error);
}

$post_name = mysqli_real_escape_string($conn, $_POST['name']);
$sql = "SELECT * FROM UserRegistrationTable WHERE name='$post_name'";
$result = $conn->query($sql);

$conn->close();
?>