How to change raid setting on the old WD mybook studio II in 2019?

i am using MACOS 10.14.3
I can not find a supporting app from WD to change my mybook studio II to raid 1 from raid 0.

do I have to use an old mac OS to do that?

Hi there,

To change the RAID configuration or RAID level please follow the below mentioned KBA-

Please know, My Book Studio-II DO NOT support JBOD or any other RAID configurations.
Note:- Changing the RAID configuration on your My Book external hard drive will erase any existing data currently on the drive. Please ensure that any existing data on the drive is backed up.