I have an APC line interactive UPS. Originally it was for my desktop, but then I got a NAS so that became the primary device. I just built me a new desktop to replace the one I turned in to my Plex server. The QNap Nas I have allows me to send a signal via the network to alert other devices on the UPS to shut down. The issue is I could never to get this to work in Windows. Linux is a bit more flexible from what I have seen.
Is there a Linux solution? Preferably something that works in Ubuntu and popOS. The Plex server runs Ubuntu and I might move the NAS over near that, as all my media is on the NAS any way. The desktop will be running popOS.