I had this question been asked in the forums a couple of times. There are two ways to achieve this.
Option 1
If you have Admin access to your Office 365 tenant, you can simply do this via the Admin portal.
Go to Admin -> Active Users
Simply click on Export Users to export the list in excel.
Option 2:
If you are not an admin, you can achieve this via Power Automate. Steps below:
Just make sure that you leave the Search term field in Search for Users action as Blank and set the Is search term required to No.
