Reset a user's password 

1. When a user requests a new password, you'll receive a password reset request in email. To reset the password, open the app launcher and select Admin. 
2. In the Microsoft 365 admin center, select Users > Active users, and then select the key icon next to the user who requested the reset. 
3. Select Auto-generate password to have a random password automatically created. 
4. Select Reset. 
5. Select the Send password in emailcheck box. 
6. You'll see your email address in the Email the new password to the following recipients box. Add the user's alternate email address or any address you choose. 
7. Choose Send email and close. 

The user will receive an email with the password reset instructions.