By default this feature This is disabled by default on Outlook Web Mail, to the mobile version of Outlook. To manually enable or disable this view it on your mobile device app:
Press the ‘house’ symbol
Select the ‘cog’ icon to go to Settings
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If you would like this view to be enabled on your Web Mail, please log a ticket via the Service Desk Portal.
Thank you & regards,
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Scroll down to the ‘Email’ section
Press the slider to turn ‘Focused Inbox’ on/off