The LAST 1.14... plex qpkg for 32 bit QNAP server

Plex Media Server NAS & Devices
2

According to the Plex Media Server announcements thread,

would be the version you’re looking to get.

If someone doesn’t say they have it, you can find a lot of old versions on Google. I’d check the SHA1 or with Virustotal if you go that route.