Php-graph-sdk: "Graph returned an error :(#100) Params cover_photo with a valid URL is required for creating a page"

[owen800q]

I tried to make an ajax call for creating a test page using a test user by following the tutorial from here https://developers.facebook.com/docs/apps/test-pages. But return an error exception,
I tried to store the test user account access token as a sesstion after it is logged in.
Supposed

$_SESSION['fb_access_token']

create_page.php

$fb = new FacebookFacebook([
'app_id' => '226057574774907', //test app_id
'app_secret' => '83e135ab7849067a4e109489cb4f1258', //test app_secret
'default_graph_version' => 'v3.0',
]);
`if (isset($_SESSION['fb_access_token']))
{

try {
    $params= array(
    "category_enum"=>"PERSONAL_BLOG",
    "name"=>"hkinstant",
    "about"=>"trying some things with the API",
    "picture"=>"https://hkinstant.me/img/banner.png",
    'cover_photo' => "https://hkinstant.me/img/cover.jpg"
  );
    //create page
    $request = $fb->sendRequest('POST', '/me/accounts', $params,$_SESSION['fb_access_token']);
}
catch (Facebook\Exceptions\FacebookResponseException $e) {
    //Wehn Graph returns an error.
    echo 'Graph returned an error :'.$e->getMessage();
    exit;
} catch (Facebook\Exceptions\FacebookSDKException $e) {
    // When validation fails or other local issues
    echo 'Facebook SDK returned an error: ' . $e->getMessage();
    exit;
}   

   $result = $request->getDecodedBody();
   echo json_encode($result);  
   }
   }`

What's wrong with the parameter "cover_photo"?

[omarojo]

'cover_photo' => "https://hkinstant.me/img/cover.jpg"
cover_photo param is not expected to be an URL but rather an OBJECT

see here:
https://developers.facebook.com/docs/graph-api/reference/user/accounts/#Creating