Hello Mounir,
sorry for the very late response.
Have you checked the developers documentation? https://docs.moodle.org/dev/Moodle_Mobile
In any case, we provide a service where we can customise the app for anyone who needs it. This service helps fund the improvement of the app in general. Our core team do not have the resources here to help people use the open source code version. https://moodle.com/mobileapp/
Regards, Juan