WC error

// KOODI

<?php

add_filter( 'woocommerce_email_classes', 'change_email_class_based_on_shipping_method', 10, 1 );
function change_email_class_based_on_shipping_method( $emails ) {
    // Get the chosen shipping method
    $chosen_shipping_methods = WC()->session->get( 'chosen_shipping_methods' );
    $chosen_shipping_method = explode( ':', reset($chosen_shipping_methods) )[0];

    // Change the email class based on the chosen shipping method
    if ( $chosen_shipping_method == 'shipping_method_0_shipit2' ) {
        $emails['WC_Email_Customer_Processing_Order'] = include( 'wp-content/plugins/kadence-woocommerce-email-designer/templates/woo/emails/customer-processing-order.php' );
    } elseif ( $chosen_shipping_method == 'shipping_method_0_local_pickup3' ) {
        $emails['WC_Email_Customer_Processing_Order'] = include( 'wp-content/plugins/breakdance/plugin/themeless/themes/breakdance-zero/woocommerce/emails/customer-processing-order.php' );
    }

    return $emails;
}

// VIRHE

PHP Fatal error:  Uncaught Error: Call to a member function get() on null in /tmp/51-woocommerce-conditional-email-template
Stack trace:
#0 /var/www/vhosts/***/wp-includes/class-wp-hook.php(308): change_email_class_based_on_shipping_method()
#1 /var/www/vhosts/***/wp-includes/plugin.php(205): WP_Hook->apply_filters()
#2 /var/www/vhosts/***/wp-content/plugins/woocommerce/includes/class-wc-emails.php(233): apply_filters()
#3 /var/www/vhosts/***/wp-content/plugins/woocommerce/includes/class-wc-emails.php(190): WC_Emails->init
#4 /var/www/vhosts/***/wp-content/plugins/woocommerce/includes/class-wc-emails.php(52): WC_Emails->__con
#5 /var/www/vhosts/***/wp-content/plugins/woocommerce/includes/class-woocommerce.php(943): WC_Emails::in
#6  in /tmp/51-woocommerce-conditional-email-template.php on line 6