Woo Commerce custom add to cart ajax handler

prefix-woo-ajax.php

<?php

add_action( 'woocommerce_ajax_added_to_cart', 'ac_add_product_custom_field' );

/**
 * 
 * @hook woocommerce_ajax_added_to_cart
 */
function ac_add_product_custom_field($product_id) {
  
  // check if logo_text has been defined by the client
	if ( isset( $_POST['logo_text'] ) ) {
		 // do something
	}
}