FOX - WooCommerce Currency Switcher Professional

Plugin: https://wordpress.org/plugins/woocommerce-product-addon/

Compatibility is implemented directly into WooCommerce Product Addons

Also into file functions.php of the current WordPress theme add next code:

add_filter('ppom_option_price', function ($price) {
    if (class_exists('WOOCS') && !empty($price)) {
        global $WOOCS;
        if ($WOOCS->is_multiple_allowed) {
            $price = $WOOCS->woocs_exchange_value($price);
        }
    }
    return $price;
});