Could not resolve host on cURL request PHP - php

Question

I'm starting to build my first API, after succesful testing on localhost(Mac OS X El Capitan) I uploaded it to my digitalocean server running Ubuntu 16.04.
I've both tried to run the cURL request from my localhost and from the server where the API is stored and both of them return "Could not resolve host" error with error number 6. My code:
On API side just
echo "200";exit;
On client side
$token = 'this is the session token';
$url = "http://xx.xx.xx.xx/API/index.php";
$data = array('username'=>'username','password'=>'password');
$datajson = json_encode($data);
$message = $url . $datajson . 'PUT';
$publishThis = base64_encode(
hash_hmac('sha256', $message, 'secret key', true)
);
$len = 'Content-Length: ' . strlen($message);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, urlencode($url));
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json',$len, 'Authorization: ' . $publishThis));
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'PUT');
curl_setopt($ch, CURLOPT_POSTFIELDS,$datajson);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, true);
$response = curl_exec($ch);
help please!!
P.S: if I remove the urlencode function the request takes for about 20 mins and ends on a 400 bad request error

Answer 1

LATER EDIT:
$token = 'this is the session token';
$url = "http://xx.xx.xx.xx/API/index.php";
$data = array('username'=>'username','password'=>'password');
$datajson = json_encode($data);
$build_query = http_build_query($data);
$message = $url . $datajson . 'PUT';
$publishThis = base64_encode(
hash_hmac('sha256', $message, 'secret key', true)
);
$len = 'Content-Length: ' . strlen($build_query);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json',$len, 'Authorization: ' . $publishThis));
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'PUT');
curl_setopt($ch, CURLOPT_POSTFIELDS,$build_query);
curl_setopt($ch, CURLOPT_VERBOSE, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, true);
$response = curl_exec($ch);
if($errno = curl_errno($ch)) {
$error_message = curl_strerror($errno);
echo "cURL error ({$errno}):\n {$error_message}";
}
echo $response;
CHANGES:
$build_query = http_build_query($data);
$len = 'Content-Length: ' . strlen($build_query);
curl_setopt($ch, CURLOPT_POSTFIELDS,$build_query)
remove url encode from CURLOPT_URL