Add new harddisk on CyberPanel for smtp mails


I am running CyberPanel on Ubuntu 20.
I added a new hardisk /dev/sdb 3.2T

mount: /mnt/sdb: /dev/sdb already mounted on /mnt/sdb.

How can I give the sdb hard drive to cyberpanel?
I can’t find any storage or disk management in CyberPanel. or to confirm that the disk is available.
I have added the hd to create an smtp server and store it on that hard drive.

Can someone help me ?

Thanks in advance!

No one can help?