We are talking about XpressU's interface. Not the Presentations you create.
All texts that come directly from XpressU will be translated. For example, buttons, menus and dialogs.
Your browser's language is used to preselect the language. But you can always choose the language when you log in.
XpressU remembers your choice for the next time, but you can change the language whenever you want.
For example, after you log in go to the top bar and click the language selector.
Language for your recipients
It is XpressU's Dialogs and User Interface that have been translated. In the image above, it is an English Presentation, so it would be natural to choose the English version of the user interface.
This is how you can work with several languages
1. First create a Presentation in one language, e.g. English
2. Then take a copy of the Presentation.
You can take a copy in two places:
In the XpressU menu down by the Timeline...
... or in the menu directly on the Presentation
3. Replace the media that is language based.
4. Translate the texts on the Presentation Settings.
Change the title and welcome message
Changing the messages for the user of your Questionnaires
5. If you use Questionnaires, translate these and replace them in the Timeline
6. Save the presentation, for example, with the same title + "DK" (for Danish).