
8h3g8 (8h3g8) asked a question.
Office 365 default domain best practices
Is it technically possible to have our O365 Default Domain federated to OKTA and if so, is it supported. I do have the O365 Deployment Guide, but really need this specific question answered.

Hi @8h3g8 (8h3g8) - I don't believe so, as you have already confirmed by reading the Okta docs. You can use the admin credentials of *.onmicrosoft.com to do the initial setup, but to federate it must be a different domain where microsoft can potentially supply one or I used a godaddy or google domain hosting service for a small fee per year.
Reference - https://help.okta.com/en/prod/Content/Topics/Apps/Office365-Deployment/configure-sso.htm