WooCommerce Subscriptions Gifting - turn off for specific products or tags

disable_gifting_by_product.php

<?php
add_filter( 'wcsg_is_giftable_product', 'disable_gifting_by_product', 12, 2 );
function disable_gifting_by_product( $is_sub, $product ) {
  $not_giftable_products = array( 906, 964 ); // add or remove product IDs here
  if ( in_array( $product->get_id(), $not_giftable_products ) ) {
    return false;
  } else {
    return $is_sub;
  }
}

disable_gifting_by_tag.php

<?php
add_filter( 'wcsg_is_giftable_product', 'disable_gifting_by_tag', 12, 2 );
function disable_gifting_by_tag( $is_sub, $product ) {
  if ( has_term( 'abc', 'product_tag', $product )  ) {
    return false;
  } else {
    return $is_sub;
  }
}