<?php
/**
 * Adding the payment fragment to the WC order review AJAX response
 */
add_filter( 'woocommerce_update_order_review_fragments', 'my_custom_payment_fragment' );

/**
 * Adding our payment gateways to the fragment #checkout_payments so that this HTML is replaced with the updated one.
 */
function my_custom_payment_fragment( $fragments ) {
	ob_start();

	my_custom_display_payments();

	$html = ob_get_clean();

	$fragments['#checkout_payments'] = $html;

	return $fragments;
}