getMediaGalleryImages() for rich snippet structured data

currently, it is only add one image to the structured data via

'image'       => $  this->getUrl('pub/media/catalog') . 'product' . $  currentProduct->getImages(), 

.i’m looking to add all media images to structured data for product page. I tried it this way but didn’t seem to work.

'image'       => $  this->getUrl('pub/media/catalog') . 'product' . $  currentProduct->getMediaGalleryImages(), 

the multiple images should be send in an array like this

"image": [   "https://example.com/photos/1x1/photo.jpg",   "https://example.com/photos/4x3/photo.jpg",   "https://example.com/photos/16x9/photo.jpg" ] 

Here is partial of the code

public function showProductStructuredData() { if ($ currentProduct = $ this->getProduct()) { try { $ productId = $ currentProduct->getId() ? $ currentProduct->getId() : $ this->request->getParam(‘id’);

        $  product = $  this->productFactory->create()->load($  productId);         $  availability = $  product->isAvailable() ? 'InStock' : 'OutOfStock';         $  stockItem = $  this->stockState->getStockItem(             $  product->getId(),             $  product->getStore()->getWebsiteId()         );         $  priceValidUntil = $  currentProduct->getSpecialToDate();         $  productStructuredData = [             '@context'    => 'http://schema.org/',             '@type'       => 'Product',             'name'        => $  currentProduct->getName(),             'description' => trim(strip_tags($  currentProduct->getShortDescription())),             'sku'         => $  currentProduct->getSku(),             'mpn'         => $  currentProduct->getSku(), //added 7-30-2019                            'url'         => $  currentProduct->getProductUrl(),             'image'       => $  this->getUrl('pub/media/catalog') . 'product' . $  currentProduct->getImages(),             'brand'       => 'mybrand', //added 7-30-2019             'offers'      => [                 '@type'         => 'Offer',                 'priceCurrency' => $  this->_storeManager->getStore()->getCurrentCurrencyCode(),                 'price'         => $  currentProduct->getPriceInfo()->getPrice('final_price')->getValue(),                 'itemOffered'   => $  stockItem->getQty(),                 'itemCondition' => 'New', //added 7-30-2019                 'url'           => $  currentProduct->getProductUrl(), //added 7-30-2019                 'availability'  => 'http://schema.org/' . $  availability             ]         ];         $  productStructuredData = $  this->addProductStructuredDataByType($  currentProduct->getTypeId(), $  currentProduct, $  productStructuredData);          if (!empty($  priceValidUntil)) {             $  productStructuredData['offers']['priceValidUntil'] = $  priceValidUntil;         }          if ($  this->getReviewCount()) {             $  productStructuredData['aggregateRating']['@type'] = 'AggregateRating';             $  productStructuredData['aggregateRating']['bestRating'] = 100;             $  productStructuredData['aggregateRating']['worstRating'] = 0;             $  productStructuredData['aggregateRating']['ratingValue'] = $  this->getRatingSummary();             $  productStructuredData['aggregateRating']['reviewCount'] = $  this->getReviewCount();         }          $  objectStructuredData = new \Magento\Framework\DataObject(['mpdata' => $  productStructuredData]);         $  this->_eventManager->dispatch('mp_seo_product_structured_data', ['structured_data' => $  objectStructuredData]);         $  productStructuredData = $  objectStructuredData->getMpdata();          return $  this->helperData->createStructuredData($  productStructuredData, '<!-- Product Structured Data by Mageplaza SEO-->');     } catch (\Exception $  e) {         $  this->messageManager->addError(__('Can not add structured data'));     } } 

}