Customize the level cost text to include the donation amount.

customize_level_cost_text.php

<?php

 /**
 * Customize the level cost text to include the donation amount.
 * link: TBD
 * 
 * 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
 */


/**
 *  Customize the level cost text to include the donation amount.
 */
function customize_level_cost_text() {
    ?>
    <script type="text/javascript">
		//Add dom ready function to watch donation amount for changes and update  level cost text total.
		jQuery('document').ready(function($) {
			 $( '#donation_dropdown' ).on( 'change', function() {
				if( $(this).val() != 'other' ) {
				//Get the selected donation amount
					const donation_amount = $(this).val();
					updateTotal( donation_amount );
				}
			});

			$( '#donation' ).on( 'change', function() {
				//Get the selected donation amount
				const donation_amount = $(this).val();
				updateTotal( donation_amount );
			});

			function updateTotal( donation_amount ) {
				const level_cost = $( '#pmpro_level_cost p' ).text();
				$('.custom-donation').empty();
				$( '#pmpro_level_cost p strong' ).after( $('<span/>')
				.addClass('custom-donation').append('( plus $ ' + donation_amount + '  ) as a donation' ) );
			}
        });

    </script>
    <?php
}
add_action( 'pmpro_checkout_after_form', 'customize_level_cost_text' );