All text displayed by the app can be modified!
While the app proposes default text out-of-the-box, you can (and probably should) modify any labels to match the style of your shop and convey your message as clearly as possible.
This video describes all the relevant sections:
Here are the sections discussed in the video you'll want to check if you want to support a different language.
Promotion code field text labels
Edit the building blocks of your offer(s):
Then click the edit button next to the building block you want to edit:
Then find the text editors. Click the text to edit it: