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Log into the office 365 admin centre.
Click Admin then Active users.
Choose Add a user.
Fill in the information for the new mailbox, which includes:
Name Fill in first, last, display name, and user name.
Select the Domain.
Password Use the auto-generated password or expand to specify a strong password for the user.
Roles Expand if you need to make this user an admin.
Click Add to create your new mailbox.
Last Updated: 7 June, 2019