Hello Youcef,
Thank you for reaching out to us.
1/ Kindly ensure that you have created a translation for the XStore Core plugin. You can refer to the following documentation for guidance: https://www.8theme.com/documentation/xstore/theme-translation/base-theme-translation/
2/ Check an answer in this topic – https://www.8theme.com/topic/back-in-stock-notifier-allignment-clickability-and-translation-options/#post-415265
Best regards,
8Theme’s Team