Thank you for posting this in Microsoft Q&A.
You can use below steps to change the name of directory,
- Login to Portal.azure.com with your account.
- Click on "Microsoft Entra ID" on the left pane.
- Then click on properties on the left pane.
- Now you can change the directory name as you want in the "Name field".
- Save the changed settings and you will have your new directory name
Let me know if you have any further questions.
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