Shortcode to display subcategories under a WooCommerce parent category

display-subcategories.php

<?php

// Shortcode example: [display_subcats id="55"]. Replace 55 with your parent category ID

add_shortcode('display_subcats', 'display_subcats');
function display_subcats( $atts, $content = null ) {
	
	$atts = shortcode_atts(
		array(
			'id'	=> ''
		), $atts);

	ob_start();

	echo '<div class="categories-wrapper">';
	
		// Other query args available here: https://developer.wordpress.org/reference/classes/wp_term_query/__construct/
		$args = array(
			'hide_empty' => false,
			'show_option_none' => '',
			'child_of' => $atts['id'],
			'taxonomy' => 'product_cat'
		);
	
		$subCategories = get_categories($args);

		foreach ($subCategories as $category) {
			
			// Other category info available here: https://developer.wordpress.org/reference/functions/get_terms/#comment-1839
			$categoryName = $category->name;
			$thumbnail_id = get_term_meta( $category->term_id, 'thumbnail_id', true);
			$categoryImage = wp_get_attachment_image($thumbnail_id, $size = 'full');
			$categoryLink = get_term_link( $category->slug, $category->taxonomy );			

			echo '<div class="category-box-wrapper">';
			echo '<div class="category-image"><a href="' . $categoryLink . '">' . $categoryImage . '</a></div>';
			echo '<h5 class="category-link"><a href="' . $categoryLink . '">' . $categoryName . '</a></h5>';
			echo '</div>';
		}
	echo '</div>';

	$content = ob_get_contents();
	ob_end_clean();
	return $content;  
}

?>