How fetch data from php mysql to flutter using post request - php

Question

Hello as i am new to flutter, i want to fetch data from php api to flutter app with json data which have multiple data's in one file
my flutter code
Future<Album> fetchAlbum() async {
final response = await http.post(
Uri.parse('https://domain/folder/api.php'),
body: jsonEncode({
"description": 'description',
"naw": "homeprod",
}),
);
if (response.statusCode == 200) {
// If the server did return a 201 CREATED response,
// then parse the JSON.
return Album.fromJson(jsonDecode(response.body));
} else {
// If the server did not return a 201 CREATED response,
// then throw an exception.
throw Exception('Failed to create.');
}
}
class Album {
//final int productid;
String description;
Album({this.description = ""});
factory Album.fromJson(Map<String, dynamic> json) {
return Album(
//productid: json['product_id'],
description: json['description'],
);
}
}
this my php code on server
if($postjson['naw']=="homeprod"){
$prod = array();
$query = mysqli_query($mysqli, "SELECT * FROM product order by rand() limit 30");
while($getpost = mysqli_fetch_array($query))
{
$prod[] = array(
'description' => $getpost['description']
);
}
if($query) $result = json_encode(array('success'=>true, 'prodlists'=>$prod));
else $result = json_encode(array('success'=>false));
echo $result;
}
always flutter return with Null data type with sub type string.
Thank you in advance