Adding HDD via USB cable

I’m trying to add additional HDD to My cloud, using USB connector behind.
However, I can’t find added HDD, either in portal site of WD Cloud, or Explorer.
May be it’s because the added HDD is quite old, ane it doesn’t match some technical requirement.

Is there some technical limitation on additional HDD to connect to My cloud by USB?
Or, is there some procedures to be done, nat just connect HDD to My cloud?

For information, additional HDD which I’m trying to connect is;
Product: IO- data HDCR-U1.0
Capacity: 1.0 TB
Connection: USB 1.1/2.0
File System: FAT32


Are you able to test that with a different drive? Just to make sure that there’s no issues with the USB port on the drive.

Thanks for reply.
Unfortunately, I don’t have other drive to check it…