Hello,
Thanks for using our theme. Please read this article – https://xstore.helpscoutdocs.com/article/30-base-theme-translation Also, create translation for XStore Core plugin also.
If translation is created already, click on Sync button – https://xstore.helpscoutdocs.com/article/103-translation-files-update , then find and translate new strings.
This https://gyazo.com/46d447daf541909f5d62bb972a360156 you can find in the Appearance > Widgets > Cart area.
If you need any further assistance, provide us with temporary wp-admin access.
Regards