Unable to get the items from Walmart API

Question

I'm trying to get item by SKU using Walmart marketplace API and following this document I'm successful in getting access token but after that when I want to get item by SKU, It fails to get item details. Please help me to find the issue. When I print 'CURLOPT_HTTPGET' it gives response back 80 and if I print '$code' it gives me 401. Seems like I have issues in request header or url but for url I use the official document of Walmart APi. So, if you find any solution, please ping me. Thanks

Here's my code:

function getWalmartDetail()
{
$data = [];
$data['client_id'] = "***********";
$data['client_secret'] = "*************************************";
return $data;
}


function getToken()
{
$data = getWalmartDetail();
$client_id = $data['client_id'];
$client_secret = $data['client_secret'];
$url = "https://marketplace.walmartapis.com/v3/token";
$uniqid = uniqid();
$authorization_key = base64_encode($client_id.":".$client_secret);
$code = "";

$ch = curl_init();
$options = array(
    CURLOPT_URL => $url,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_TIMEOUT => 60,
    CURLOPT_HEADER => false,
    CURLOPT_POST => 1,
    CURLOPT_POSTFIELDS => "grant_type=client_credentials",
    CURLOPT_HTTPHEADER => array(
        "WM_SVC.NAME: Walmart Marketplace",
        "WM_QOS.CORRELATION_ID: $uniqid",
        "Authorization: Basic $authorization_key",
        "Accept: application/json",
        "Content-Type: application/x-www-form-urlencoded",
    ),
);
curl_setopt_array($ch,$options);
$response = curl_exec($ch);
$code = curl_getinfo($ch,CURLINFO_HTTP_CODE);
curl_close($ch);

if($code == 201 || $code == 200)
{
    $token = json_decode($response,true);
    return $token['access_token'];
}

}


 $token = getToken();
 $data = getWalmartDetail();
 $client_id = $data['client_id'];
 $client_secret = $data['client_secret'];
 $authorization = base64_encode($client_id."+".$client_secret);
 $url = "https://marketplace.walmartapis.com/v3/items/1234567?productIdType=SKU";

 $ch = curl_init();
 $qos = uniqid();
 $options = array(
 CURLOPT_URL => $url,
 CURLOPT_RETURNTRANSFER => true,
 CURLOPT_TIMEOUT => 60,
 CURLOPT_HEADER => false,
 CURLOPT_HTTPHEADER => array(
    "WM_SVC.NAME: Walmart Marketplace",
    "WM_QOS.CORRELATION_ID: $qos",
    "Authorization: Basic $authorization",
    "WM_SEC_ACCESS_TOKEN: $token",
    "Content-Type: application/json",
    "Accept: application/json",
    ),
    CURLOPT_HTTPGET => true,
    );
    print_r(CURLOPT_HTTPGET);
    curl_setopt_array($ch, $options);
    $response = curl_exec($ch);
    $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    print_r($code);
    curl_close($ch);

    if ($code == 201 || $code == 200){
    $response = json_decode($response,true);
    echo "<pre>";
    print_r("Hey");
    exit();
    } else{
    print_r("No");
    return false;
    }