See the following documentation on translations and language:
https://docs.mendix.com/refguide/translatable-texts
https://docs.mendix.com/refguide7/project-settings#5-1-default-language
A user(or account) is linked to a system.language entity. By settings this language after login the the user will see the application in its set language.
You have to think seperately to text wich is generated programmatically and text on the ui (pages)
Programmatically;
- check in your microflow which language object is associated to user (via account) and generated the text based on that setting (or consider a tabel wherein you maintain your text for different languages, which can be retrieved in mf)
UI:
- You should have extended the project language settings with those languages
- choose a default language (this will change the text of all pages to the chosen language value)
- change the text of the page
- change the default language and update again the texts.