Backup Manager must be installed on a Windows system. It can be the same machine where Oracle is located or a different one. In the latter case Backup Manager connects to Oracle remotely through Oracle Client. You will need to configure some remote connection settings before you start backups (Pre-backup settings for remote access to Oracle).
Read and write access to the backup folder is required.
The backup folder must have a sufficient amount of free space. The amount of space you will need depends on the database size and on your retention settings.
For example, if the size of generated .bck files during one session is 15 GB and "Retention in backup counts" is set to 1, you need at least 30 GB of free space.
Please be aware that due to data compression changes the size of the backup folder in the recent versions has increased in comparison to versions 15.9-15.12. However, the amount of data submitted to storage has decreased and is going to decrease further as you continue delta backups.