Display additional content after "Add to cart" button on product page for declared categories

functions.php

add_action( 'woocommerce_after_add_to_cart_button', 'studiowp_woocommerce_after_add_to_cart_button' );
function studiowp_woocommerce_after_add_to_cart_button() {
	global $product;
	$my_categories = array( 15, 16 );
	$is_my_category = false;
	$product_categories = $product->get_category_ids();
	foreach ( $my_categories as $my_category ) {
		if ( in_array( $my_category, $product_categories ) ) {
			$is_my_category = true;
		}
	}
	if ( $is_my_category ) {
		?>
		<div>My content</div>
		<?php
	}
}