I can insert different prices, error

Hi, when I enter the product option I can insert the normal price but instead of your plugin there’s this error:
Warning: Invalid argument supplied for foreach() in /web/htdocs/www.francescopolese.it/home/demo/wp-content/plugins/woocomerce-price-by-country/woocommerce-price-by-country.php on line 746

Can I fix it?
Thank you
Francesco P.

https://wordpress.org/plugins/woocomerce-price-by-country/