Removes the "Pay with PayPal Express" choice from the checkout page when the user uses one of the specified Membership Level IDs

disable-paypalexpress-for-level.php

<?php
/*
Plugin Name: PMPro Customizations: Remove PayPal Express as payment option for Membership Level
Plugin URI: https://eighty20results.com/paid-memberships-pro/do-it-for-me/
Description: Removes PayPal Express as a payment option on the PMPro Checkout page when the user has selected a specific membership level.
Version: 1.0
Author: Eighty / 20 Results by Wicked Strong Chicks, LLC <thomas@eighty20results.com>
Author URI: https://eighty20results.com/thomas-sjolshagen/
License URI: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
License: GPLv2 or later

 * Copyright (c) 2018 - Eighty / 20 Results by Wicked Strong Chicks.
 * ALL RIGHTS RESERVED
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * Remove the PayPal Express or Credit Card payment option from the PMPro checkout page
 * when selecting a membership level with the specified $level_to_exclude_paypal_from (integer)
 */
function remove_paypalexpress_from_use_for_level() {
	
	global $pmpro_pages;
	
	/**
	 * @param int[] $level_to_exclude_paypal_from - A comma separated list of Membership Level IDs where
	 *                                            you want to remove PayPal Express as an payment option
	 *                                            for Paid Memberships Pro
	 *                                            (When the 'Add PayPal Express Option at Checkout' add-on
	 *                                            is installed)
	 */
	$level_to_exclude_paypal_from = array( 1, );
	
	if ( !isset( $pmpro_pages['checkout'] ) || is_page( $pmpro_pages['checkout'] ) ) {
		return;
	}
	
	$level_id = isset( $_REQUEST['level'] ) ? intval( $_REQUEST['level'] ) : null;
	
	if ( empty( $level_id ) || $level_to_exclude_paypal_from !== $level_id ) {
		return;
	}
	
	if ( ! function_exists( 'is_plugin_inactive' ) ) {
		require_once( ABSPATH . '/wp-admin/includes/plugin.php' );
	}
	
	if ( is_plugin_inactive( 'pmpro-add-paypal-express/pmpro-add-paypal-express.php' ) ) {
		return;
	}
	
	remove_action( 'pmpro_checkout_boxes', 'pmproappe_pmpro_checkout_boxes', 20 );
}

add_action('init', 'remove_paypalexpress_from_use_for_level', 99 );