Plex media server update

Server Version#: 1.18.6.2350-143d2e66b
Player Version#:

Hello,
I would appreciate some help. I use WD My Cloud Home Duo. There is preinstalled Plex media server, version 1.18. I would like to update it to actual version 1.21. But there is the problem that i can’t see my device (WD My Cloud Duo) on official support server https://plex.tv/downloads. Could you please somebody help me?

Radek

I don’t have any help but I too want this ability…I wish WD would give the ability to update its preinstalled apps…