Specifies whether the alert includes a suppression checkbox, which you can employ to allow a user to opt out of seeing the alert again.
The default value of this property is false, which specifies the absence of a suppression checkbox in the alert. Set the value to true to show a suppression checkbox in the alert.
By default, a suppression checkbox has the title, “Do not show this message again.” In macOS 11.0 and later, if the alert displays multiple buttons that prompt the user to make a choice, the title is “Do not ask again.” To customize it, use the checkbox’s title property, as follows: