Yes you can up to 32GB is supported. Once you insert it it will send messages to QSYSOPR indicating that it has configured it. It looks like an optical drive.
The other option is to use an RDX drive which is natively supported (as an optical drive), connects to the USB port, and is bootable in case you need to reload the server. The RDX drive was supported for just this situation where a tape drive is very expensive for the needed capacity.