<?php
if ( function_exists( 'YITH_YWRAQ_Order_Request' ) ) {
add_action( 'wp_loaded', 'ywraq_upsell_in_cart', 11);
function ywraq_upsell_in_cart() {
remove_filter( 'woocommerce_add_to_cart_validation', array(
YITH_YWRAQ_Order_Request(),
'cart_validation'
), 10, 2 );
}
}