As Ronald says, you should just be able to change reference between the currentUser and the language you require.
Something like this should work. $currentUser is a variable that should be available by default to your microflow, and not something you need to retrieve. You will need to retrieve the correct Language though.
You need to change the reference between user and language (User_Language). So retrieve the current user and change this reference to the selecte language.
In addition to the answers above I have an old ticket with support on this. Be sure to change to language in a microflow and not a nanoflow..:
Daria Nerush (Mendix)
Sep 25, 2020, 12:41 GMT+2
Thank you for your patience on this request.
I have a response from the R&D team that System. Language is read-only for offline-applications. We don’t have a way of changing the language in offline applications at the moment.
There is already a story with our dedicated R&D team. But unfortunately, we can not provide you the ETA for now.
Please, let me know if you want to be updated on this and if you have any other outstanding questions.
Technical support engineer
In addition to Robert’s answer, I changed the language object to match the user’s selection as follow:
and when it returns to the nanoflow it reload the app (mx.reload() )
Is that process correct?
Because when the user changes the language (the default is english) from english to arabic it works, but when they want to return to english it doesn’t work, the app language is still arabic