my-pmpro-h2-to-h5-no-access-message-html.php

<?php
/**
 * Replace <h2> with <h5> in the no access message HTML.
 *
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */
function h2_to_h5_no_access_message_html( $no_access_message_html, $level_ids ) {
	// replace <h2> with <h5>
	$no_access_message_html = str_replace( '<h2', '<h5', $no_access_message_html );
	$no_access_message_html = str_replace( '</h2>', '</h5>', $no_access_message_html );

	return $no_access_message_html;
}
add_filter( 'pmpro_no_access_message_html', 'h2_to_h5_no_access_message_html', 10, 2 );