How can I skip a user task?

Hello,
is it possible to skip a user task so that it is displayed as done?
The use case is as follows: A user should be able to complete an assigned task without having started to work on it (the work item is only displayed as completed without any execution being attempted/carried out). In this way, unimportant/non-critical tasks can be skipped.

If this is possible, is there a way to handle data that the skipped task should have provided for subsequent tasks? Is it possible to specify default values here? Or can such tasks simply not be enabled to be skipped?

Many thanks in advance!