How do I add drives to this MyCloud Duo?

Best Buy stores has this My Cloud Duo for sale but it is Diskless.
It comes with NO hard drives.

How would I go about adding drives ?
Don’t I need to format and install the MyCloud operating system
Onto the drive before I add it to the Duo ?

Hi @alexi7,

Please refer to the article My Cloud: Physically install and connect a WD NAS device to a home or small office network:

If further assistance is needed, please open a case with our support team at the following: