Hi,
Thank you for posting in Microsoft Q&A forum.
1,Please make sure you are licensed for Intune and enabled MDM authority.
Set the mobile device management authority
2,You can try to activate the basic mobility and security service as described here. The activation took a few hours to kick in.
Set up Basic Mobility and Security
Similar thread for your reference:
401 and 403 error when logging into endpoint admin center
Thanks for your time. Have a nice day!
Best regards,
Simon
If the response is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.