You may have issues translating the shopping cart steps on the Cart and Checkout pages in Jupiter theme, when you have already translated the theme strings, but the steps text is missing in your translation file.
In this case you need update your translation .po file with the default Jupiter .pot file.
If you use Poedit software, then to update your .po file, navigate to Catalog, choose Update from POT file, and then choose the .pot file from which you would like to get updated contents (usually it’s mk_framework.pot in jupiter/languages directory). The missing strings will appear. Next, translate the project as you would normally do and save all changes.
If you use Loco Translate plugin, to update the translation, click on Sync button on the translation edit screen. This option will sync the old translations with new translations.
Translate the text you need and save the changes.