Have a problem on checkout page

Hi,

I received this error on the checkout page after updated to latest version

Fatal error: Uncaught Error: Cannot use object of type WC_Checkout as array in /var/www/vellabox.com/public_html/wp-content/plugins/klaviyo/includes/wck-cart-functions.php:149 Stack trace: #0 /var/www/vellabox.com/public_html/wp-includes/class-wp-hook.php(303): kl_checkbox_custom_checkout_field(Object(WC_Checkout)) #1 /var/www/vellabox.com/public_html/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters(NULL, Array) #2 /var/www/vellabox.com/public_html/wp-includes/plugin.php(470): WP_Hook->do_action(Array) #3 /var/www/vellabox.com/public_html/wp-content/plugins/woocommerce/templates/checkout/form-shipping.php(51): do_action(‘woocommerce_bef…’, Object(WC_Checkout)) #4 /var/www/vellabox.com/public_html/wp-content/plugins/woocommerce/includes/wc-core-functions.php(345): include(‘/var/www/vellab…’) #5 /var/www/vellabox.com/public_html/wp-content/plugins/woocommerce/includes/class-wc-checkout.php(301): wc_get_template(‘checkout/form-s…’, Array) #6 /var/www/vellabox.com/public_html/wp-includes/class-wp-hook.php(303) in /var/www/vellabox.com/public_html/wp-content/plugins/klaviyo/includes/wck-cart-functions.php on line 149

Let me know how to fix it. Thanks!