@Maggie Thanks for posting in our Q&A. For this issue, it is not related windows 365. It is related to Microsoft 365 license.
For this issue, I have done a lot of research. I find some information about these two licenses' Feature availability.
Defender for Office 365 Plan 1:
https://learn.microsoft.com/en-us/office365/servicedescriptions/office-365-advanced-threat-protection-service-description#feature-availability
Enterprise Mobility + Security E5:
https://www.microsoft.com/en-us/microsoft-365/enterprise/e5?activetab=pivot%3aoverviewtab
Please click on "Full comparison (PDF)".
Based on my experience, Enterprise Mobility + Security E5 includes intune and Azure AD licenses. If you have Enterprise Mobility + Security E5, we can manage your organization’s devices and apps with intune.
To get more accurate help, it is suggested to contact Licensing support. Here is the support link:
https://www.microsoft.com/en-us/licensing/default?rtc=1
Hope it will help.
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