Introduction
The Outlook mobile app does not show the notes you make in the Outlook 365 application on Windows and Mac. Where are they?
Instructions
You must install the OneNote application available through Company Portal (iOS) or the Google Playstore (Android) to be able to see your notes--renamed "Sticky Notes."
This article from Microsoft provides the essential information.
Simply put, notes created in Outlook 365 synchronize with the Sticky Note application in Windows and the OneNote mobile application. A note you create in any of those applications will appear in the others.
In both iOS and Android, the OneNote application has an icon in the lower right that when tapped will open a full list of your notes.