Get current product id inside a function

I have a custom plugin to generate pdf of my products. I am calling this function inside the plugin to get all the gallery images of a product.

    function get_gallery_images(){
      $product_id = 34560;
      $product_obj = new WC_product($product_id);
      $attachment_ids = $product_obj->get_gallery_image_ids();
    }

This function works perfectly when the id of the product is fixed, but whenever I try to get the ID dynamically is stops working. My dynamic function is:

function get_images(){
  global $product;
  $attachment_ids = $product->get_gallery_image_ids();
}

It should work because I have seen people using this function but it doesn’t work for me and I am unable to identify the issue.