Navigate to Users > Active users in the left pane.
Choose Add a user.
Enter the Display name and Username (first name and last name are optional).
Uncheck Automatically create password (if already checked) and provide a password of your choice. Check the box to let the system generate a password for you.
Click Next.
A service account does not require a license. To create a service account without a license, select your usage location and then select Create user without product license.
Click Next.
Under the Roles option, select Admin center access and choose the required roles (the Exchange Admin role is mandatory).