You could follow the steps to change your display name:
- In the admin center, go to the Users > Active users page.
- Select the user's name, and then on the Account tab select Manage contact information.
- In the Display name box, type a new name for the person, and then select Save.
If you get the error message "We're sorry, the user couldn't be edited. Review the user information and try again, see Resolve error messages.
It might take up to 24 hours for this change to take effect across all services. After the change has taken effect, the person will have to sign in to Outlook, Skype for Business and SharePoint with their updated username.
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