NUT addon compatible mini ups / powerbank

Hi everyone, is there any mini ups compatible with the NUT addon? (
I’d like to only plug a modem, a router and a Raspberry Pi 3b to the ups, I don’t need a big and expensive one. I want to use the NUT addon to notify me the power outage and turn off Home Assistant before power goes off.

I’m using Eaton 3S 550VA
Just a kind of an extension cord with 3 sockets for battery (my HUE Hub, NUC and Modem)

Works great wit NUT component, the USB from UPS (so many acronyms) goes to my NUC and Linux gives access to the status for network.

Just switched battery for the UPS in January, last one was ~5 years old.

Could You please share Your NUT configuration? I have recently installed exactly the same UPS (3S 550VA) and I can’t get it to work properly