PHP: Using API Key in CURL GET Call

I saw a post for using an api key to authenticate messages in curl. I have a GET call that requires apikey to authorize, i.e. the request must have an authorization header containing an apiKey. I got the api key and try to use it for the GET call:

<?php

$service_url = 'http://localhost/finals/task_manager/v1/tasks/Authorization:'.$apiKey;
$curl = curl_init($service_url);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
$curl_response = curl_exec($curl);
if ($curl_response === false) {
    $info = curl_getinfo($curl);
    curl_close($curl);
    die('error occured during curl exec. Additioanl info: ' . var_export($info));
}

curl_close($curl);
$decoded1 = json_decode($curl_response,true);
if (isset($decoded1->response->status) && $decoded1->response->status == 'ERROR') {
    die('error occured: ' . $decoded1->response->errormessage);
}
echo 'response ok!';
var_export($decoded1->response);
?>

      

        
        
        
      

    

I am getting error in json response:

{"error":true,"message":"Api key is misssing"}

      

        
        
        
      

    

I tried several other ways how to pass the headers array, but I keep getting the error. How do I get curl_response correctly? How do I pass the authorization header that the api key uses?

The api for the get call I am doing is created (created using Slim Library):

index.php
/**
 * Listing all tasks of particual user
 * method GET
 * url /tasks          
 */
$app->get('/tasks', 'authenticate', function() {
            global $user_id;
            $response = array();
            $db = new DbHandler();

            // fetching all user tasks
            $result = $db->getAllUserTasks($user_id);

            $response["error"] = false;
            $response["tasks"] = array();

            // looping through result and preparing tasks array
            while ($task = $result->fetch_assoc()) {
                $tmp = array();
                $tmp["id"] = $task["id"];
                $tmp["task"] = $task["task"];
                $tmp["status"] = $task["status"];
                $tmp["createdAt"] = $task["created_at"];
                array_push($response["tasks"], $tmp);
            }

            echoRespnse(200, $response);
        });

      

        
        
        
      

    

Authentication function:

in the same index.php file
/**
 * Adding Middle Layer to authenticate every request
 * Checking if the request has valid api key in the 'Authorization' header
 */
function authenticate(\Slim\Route $route) {
    // Getting request headers
    $headers = apache_request_headers();
    $response = array();
    $app = \Slim\Slim::getInstance();

    // Verifying Authorization Header
    if (isset($headers['Authorization'])) {
        $db = new DbHandler();

        // get the api key
        $api_key = $headers['Authorization'];
        // validating api key
        if (!$db->isValidApiKey($api_key)) {
            // api key is not present in users table
            $response["error"] = true;
            $response["message"] = "Access Denied. Invalid Api key";
            echoRespnse(401, $response);
            $app->stop();
        } else {
            global $user_id;
            // get user primary key id
            $user = $db->getUserId($api_key);
            if ($user != NULL)
                $user_id = $user["id"];
        }
    } else {
        // api key is missing in header
        $response["error"] = true;
        $response["message"] = "Api key is misssing";
        echoRespnse(400, $response);
        $app->stop();
    }
}