Hi fernandoportela, Merry Christmas, and Happy New Year. Thanks for purchasing the plugin, please check the screenshots here https://www.codester.com/items/4739/whatsapp-share-woocommerce-plugin
of plugin settings, i am sure screenshots can help you. if whatsapp icon still doesn't appear on the feel free email me on my email [email protected]
along with screenshots, i will help you to find the issue.