Try to add ups it is not need to seen in port if using usb ups.
Only APC ups are supported.
Here is picture from 750UP with APC Back-up 650 ups.
Version is 6.23 if you ask for ROS version.
I have couple 750UP and also 411U and 433GL with working APC UPS usually use ACP Back-UPS 650 and some time Smart UPS 750 but Smart UPS connected using USB to serial port converter or serial port because give more information compare to USB connection (not tested in new version in older version 6.1x some status missing if connected to USB directly).
There is bug if using UBS to serial converter after RB reboot UPS is missing need to add it again.
Now I replacing UPS with power supply with ups function and in next couple months replace all UPS, longer work on battery, smaller.
If some one have question ask I have for now couple UPS connected to 411U 750UP 433GL some of then using USB to serial converter I can try it if someone need something to test
on working system.