Throw and Alert when a custom button is not pressed

I want to use it in my if statement that-> if my custom button is not pressed, throw an alert that you didn’t pressed this button. I am unable to capture the event on how to get whether the custom button is pressed or not

Set a flag when the button is pressed. Check if your flag is set, if not, show alert.

This is a weird workflow, if users are not clicking that button, something is wrong in the workflow.