Your title is worded in a way that suggests that Ukrainian citizens are ready to sue for peace, but the actual study doesn’t conclude that at all. Vast majorities of those surveyed believe that Ukraine will win the war and restore their original territory.
The options available were, basically, “the war can only end through military means” and “in addition to the military efforts, diplomatic efforts should be taken to end the war”. It isn’t particularly surprising that people understand that diplomatic efforts are necessary to conclude the war, but this shouldn’t be taken as a sign that they’re ready to simy give up. Far from it.