Add small notice above submit button that charges are in USD for Paid Memberships Pro

pmpro-before-submit-button-text.php

<?php
/**
 * Add a small message above the submit button at checkout that charges will be done in USD.
 * To add this code to your site, please follow this guide - https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */
function my_pmpro_add_message_before_submit_button() {
	echo "<em>Please note that all charges will be processed in USD (United States Dollars).</em>";
}
add_action( 'pmpro_checkout_before_submit_button', 'my_pmpro_add_message_before_submit_button' );