On pretty much every computer I’ve seen since ATX became a thing, pressing and holding power for I think 6 seconds (but could be another specific time) has force powered off the whole thing. Hibernation should kick in on a single press if you have it configured that way and trigger on the release of the button.
Hold the power button for 10 seconds!
Unless pressing the power button triggers hibernation.
On pretty much every computer I’ve seen since ATX became a thing, pressing and holding power for I think 6 seconds (but could be another specific time) has force powered off the whole thing. Hibernation should kick in on a single press if you have it configured that way and trigger on the release of the button.