$url = 'https://api.wachat.net/send';
$mediaurl = '$mediaurl';
$data = [
'receiver' => '$receiver',
'msgtext' => 'Testing send message through API',
'token' => '$token',
'mediaurl' => $mediaurl, // delete this line if no media
];
$ch = curl_init();
curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: application/x-www-form-urlencoded']);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'POST');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_TIMEOUT, 30);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
$response = curl_exec($ch);
curl_close($ch);
echo $response; // output {success:true} or {success:false}
Note : don't forget to URL encode your query params like base64 or utf-8