Hi,

You should be able to translate it with String translations in WPML. The only thing is that we forgot to add it to the WPML config. To fix this, you need to edit wpml-config.xml in the theme root folder and add the following line. We will fix this in our next update
https://prnt.sc/q6yx1f

<key name="thank_you_page_extra_content"/>

Regards