WCFM-PayPal-Membership-Payment-404-bad-link

add_filter('wcfm_memberships_payment_paypal_args', function($body, $wcfm_membership_payment_form_data) {
    $item_name = $body['item_name'] ?? 'membership plan';
    $body['item_name'] = substr($item_name, 0, 20);
    return $body;
}, 10, 2);

add_filter( 'wcfm_memberships_payment_paypal_url', function($paypal_url) {
    $wcfm_membership_options = get_option('wcfm_membership_options', []);
    $membership_payment_settings = [];

    if (isset($wcfm_membership_options['membership_payment_settings'])) {
        $membership_payment_settings = $wcfm_membership_options['membership_payment_settings'];
    }

    return isset($membership_payment_settings['paypal_sandbox']) ? "https://www.sandbox.paypal.com/cgi-bin/webscr" : "https://www.paypal.com/cgi-bin/webscr";
} );