1. after download Android version moodle apk, then install it. I find its language will be set to cellphone's. this is perfect.
2. but when do above step via iphone, when open it first time, app language always is ENGLISH, even if my cellphone is Italian language. can i change this situation?
I have read the FAQ, but my mobile system is Italian, when install moodle via app store, it's English Language.
How can I get the app in my language?
The Moodle app automatically detects your mobile's language and displays in the same language (if the translation exists). Otherwise, you can set the app language in App settings > General.
If the Moodle app is not yet available in your language, please contribute a translation! See Translating Moodle Mobile for details of what to do.
I just tested this in an iPhone and iPad and the app displayed the italian language as it should. Basically I:
-Uninstalled the app I had previously installed.
-Changed the iPad and iPhone language to Italian (in Settings > General > Language).
-Install the Moodle app again and open it. The app language was set to Italian.
Please notice that some strings will still be seen in English because they haven't been translated to italian yet.
If the issue still happens to you can you please tell us which iOS version are you using? I tested this in 12.3.1 and 13.4.1.