Identifier returned as the action when this button is pressed.
OptionaldefaultWhether this button is the default (activated on Enter).
OptionaliconOptional icon class (e.g. a Font Awesome class).
OptionallabelButton label (defaults to action).
A button in the generic
dialogprimitive.Pure, Foundry-free description of a dialog button — the
dialogboundary function maps it onto the underlying Foundry dialog implementation.