$new_issue = array(
            'fields' => array(
                'project' => array('key' => "KEY"),
                'summary' => $this->Summary,
                'description' => $this->Description,
                'issuetype' => array('name' => 'Bug')
            )
        );

        $body = json_encode($new_issue);

 self::$handle = curl_init();

 curl_setopt(self::$handle, CURLOPT_CUSTOMREQUEST, "POST");
 curl_setopt(self::$handle, CURLOPT_POSTFIELDS, $body);
 curl_setopt_array(self::$handle, array(
    CURLOPT_URL => "jiraUrl//rest/api/2/issue/",
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_FOLLOWLOCATION => true,
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_HTTPHEADER => array("content-type:application/json"),
    CURLOPT_HEADER => true,
    CURLOPT_SSL_VERIFYPEER => false,
    CURLOPT_ENCODING => ''
    CURLOPT_HTTPAUTH => CURLAUTH_BASIC,
    CURLOPT_USERPWD => $username . ':' . $password
      ));


     $response   = curl_exec(self::$handle);
            $error      = curl_error(self::$handle);

CURLOPT_URL => "jiraUrl//rest/api/2/issue/

CURLOPT_URL => "$jiraUrl//rest/api/2/issue/",

$url = "http://your.domain.here/rest/api/latest/issue/"
$username = "username";
$password = "password";
$txt = '{
    "fields": {
        "project": {
            "key": "KEY"
        },
        "summary": "SUMMARY",
        "description": "DESCRIPTION",
        "issuetype": {
            "name": "ISSUETYPE"
        }
    }
}';

// Create a new cURL resource
$ch = curl_init ();

// Set URL and other appropriate options
curl_setopt ( $ch, CURLOPT_URL, $url );
curl_setopt ( $ch, CURLOPT_RETURNTRANSFER, 1 );
curl_setopt ( $ch, CURLOPT_POSTFIELDS, $txt );
curl_setopt ( $ch, CURLOPT_POST, 1 );
curl_setopt ( $ch, CURLOPT_USERPWD, $username . ":" . $password );

$headers = array ();
$headers [] = "Content-Type: application/json";
curl_setopt ( $ch, CURLOPT_HTTPHEADER, $headers );

// Grab URL and pass it to the browser
$result = curl_exec ( $ch );

echo $result;