Check the My Cloud Dashboard to see what firmware version you are using. Firmware v4.x is for the first gen single bay My Cloud units. The v2.x firmware for the single bay My Cloud units is for the second generation version and that version wasn’t released to the consumer market until sometime around October 2015.
If you actually have a first generation v4.x single bay My Cloud then you may want to look at the following discussion which explains how to use SSH to install an unofficial mod that allows for remote mapping of the My cloud similar to how one used to be able to remote map a My Cloud using the MyCloud.com web portal before WD removed that feature well over a year ago.
https://community.wd.com/t/app-clouddavmod-various-versions-for-firmware-v4-12-2016/161543
v4.x Single Bay My Cloud User Manual: http://products.wdc.com/library/?id=439&type=25&cn=4779-705103&lang=en
v2.x Single Bay My Cloud User Manual: http://products.wdc.com/library/UM/ENG/4779-705147.pdf
