Principle: Yes, PBS can!
Detailed: It depends largely on how this hard drive is integrated into the VM and how you want to perform your backup with the PBS. A properly passed hard drive is not included in the backup of the VM via Proxmox VE, so you would have to make a data backup explicitly for this drive from the VM.
There is simply no detailed information about your setup so that you can really say that PBS will backup it or not.
The other question is whether simply backing up data from the hard drive will do you any good at all. Can you do something with this data backup later or does it possibly have dependencies?
It may be better if you have a VM or the node that has the volume mounted and can read the data 1:1 (if Minio allows such access). Then you can actually back up the files using this VM or node and you don't have to rely on the installed solution to access this data.