WPML allows you to create multilingual WooCommerce sites with the help of the WooCommerce Multilingual (WCML) module. The language of the product page gets varied based on the language that the shopper chooses.
Using the WPML string translation, you can translate the texts of the extra product options like the label, description, confirmation message, etc.
For a basic guide about installing and configuring WPML, see here.
Once the plugins are installed and configured, you can easily translate the WooCommerce Extra Product Option strings. For that,
Navigate to WPML > String Translation.
From the dashboard, select the woocommerce-extra-product-options-pro domain and click on the search button to list the related strings.
Now, click on the translations link corresponding to the string that you need to translate. It gets expanded and you can provide the text for each language.
Also, make sure that you are translating the default WooCommerce strings.
Once the changes are done, click on the Save button.To know more about String Translation, Click Here.