My Cloud EX4 Drive Fault

The NAS drive is still working. I have 2 drives with RAID 1 configuration. One drive bay has a red LED fault light on and the dashboard shows “Drive Status FAULT”. Is it possible to replace just one drive without loosing data? I have 2 unused drive bays available. Just add 1 or 2 new disks?

Screenshots:

Running System Test now… (seems to take forever.)

see here

https://support-en.wd.com/app/answers/detail/a_id/15992

in short, you just replace the drive and the system will rebuild the RAID1.