Set up email in the Outlook for Android app 

https://support.office.com/en-us/article/set-up-email-in-the-outlook-for-android-app-886db551-8dfa-4fd5-b835-f8e532091872​ 

Set up email in the Outlook for iPhone/iPad app 

https://support.office.com/en-us/article/set-up-email-in-outlook-for-ios-mobile-app-b2de2161-cc1d-49ef-9ef9-81acd1c8e234​