Bad token (probably) on rest api call to Patch GatewayDatasource (403 Forbidden error)

Hello guys,

I am trying to update datasource credentials of dataset, first I am getting response of "Get GetBoundGatewayDatasources" with ID and Gateway id without any problems
Later on I am calling to "Patch GatewayDatasource" without any luck. I am getting 403 Forbidden error.
All the call I used before allowed me to use AppKey instead of token, unfortunately "Patch GatewayDatasource" seems like allows only tokens, because when I do use AppKey I am getting error that Token is not detected on Json, newerthless they tell us AppKey or Token is allowed: https://msdn.microsoft.com/en-us/library/azure/mt711498.aspx

This is how I am getting token, and I do believe something is wrong here:

public function getDashboardToken($workspaceId,$reportId) {

		$key = env('ACCESS_KEY');
		$collection_name = env('WORKSPACE_COLLECTION');
                $payload = [
                    "ver" => "0.2.0",
                    "type" => "embed",
                    "wcn" => $collection_name,
                    "wid" => $workspaceId,
                    "rid" => $reportId,
                    "iss" => "PowerBISDK",
                    "aud" => "https://analysis.windows.net/powerbi/api",
                    "exp" => time()+60*60,
                    "nbf" => time()
                ];
                $tokenListing = JWT::encode($payload, $key);
                return ($tokenListing);
		}

This is my method for "Patch GatewayDatasource":

$ch = curl_init();

$data = array('credentialType' => 'Basic',
			'basicCredentials'=>array(
						'username' => 'username',
						'password' => 'password',
					)
			);
$token = $this->getDashboardToken($workspaceId, $datasetId);

$headers = array();
$headers[] = "Authorization: AppToken " . $token;
$headers[] = 'Content-Type: application/json; charset=utf-8';

curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

curl_setopt($ch, CURLOPT_URL, "https://api.powerbi.com/v1.0/collections/".$collection_name."/workspaces/".$workspaceId."/gateways/".$gatewayId."/datasources/".$datasource_id."/");

curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "PATCH");

curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
// curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); //Might be required for https
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));
            				
$response_json = curl_exec($ch);

$httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

Many thanks!