The one I got off Amazon for like $25 is only slightly more difficult than replacing your toilet seat. Remove the existing toilet seat, screw this one in, put your toilet seat back on, connect to the water inlet the toilet uses. About a 30-45 minute job in total.

There’s no electronics because it uses the water pressure to push the water through, so it’ll work even with the power out.

Especially good for renters because it’ll be just as easy to remove and leaves no permanent change.