Magento 2 how to get Postcode from billing address in observer?

I cannot get the postcode from Users’s billing Address,this is my code, everything works fine except for the postcode, which i’m not able to pull.

$  objectManager = \Magento\Framework\App\ObjectManager::getInstance();          $  customer = $  observer->getEvent()->getCustomer();         $  customer_email=$  customer->getEmail();         $  first_name= $  customer->getFirstname();         $  last_name= $  customer->getLastname();         $  taxVat = $  customer->getTaxvat();           //Billing Address variables          $  billingID = $  customer->getDefaultBilling();         $  billingAddress = $  objectManager->create('Magento\Customer\Model\Address')->load($  billingID);         $  billingCompany = $  billingAddress->getCompany();         $  billingZipcode = $  billingAddress->getPostCode();         $  billingCity = $  billingAddress->getCity();         $  billingState = $  billingAddress->getRegion();         $  billingStreet = $  billingAddress->getStreet();         $  billingStreet1 = $  billingStreet[0];         $  billingStreet2 = $  billingStreet[1];         $  billingTelephone = $  billingAddress->getTelephone(); 

Greetings!