Veeam Backup for Microsoft Office 365 is a standalone solution. We do advise to install it on a VM and backup that VM with B&R for the 3-2-1 rule. VBO365 is different from B&R because the database that contains the backup of the emails is a running database and not a static backup file.
For licensing, we are running a promo (https://go.veeam.com/promo-free-backup- ... -emea.html
) that will give you free licenses depending on what edition of B&R you have today
Hope it helps