'{username}', 'apiKey' => '{apiKey}', )); $service = $client->loadBalancerService(null, '{region}'); // Retrieve your load balancer $lb = $service->loadBalancer('{loadBalancerId}'); // Blacklist an IP range $lb->createAccessList(array( (object) array( 'type' => 'DENY', 'address' => '{ipAddressRange}' // Replace with your own CIDR ) ));