WooCommerce | Add custom text to a particular product ID variation area

woocommerce-add-custom-text-to-product-id-variation-area.php

<?php

//hook our function to the product variation
add_action( 'woocommerce_single_variation', 'fs_custom_variation_text', 18 );

function fs_custom_variation_text() {
	global $product;

	// checking if the product is the correct product id
	if ($product->id === 454) {

	// custom text
	echo '<div class="product-addon"><h3 class="addon-name">Your Custom Title</h2>
		<div class="addon-description"><p>Add whatever text or HTML that you want to.</p></div></div>';
	}
}