Requirement

we have to customize the assignment submit to conditionally show confirmation modal window.

example:

on submit of an assignment we have check if a specific property(IsNotificationApplicable) is set to 'true'. if set to 'No' submit the assignment without showing the modal window. if set to 'true' then show a modal box in which user should be allowed to add multiple workparites whom me need to notify over the email.

How should we achieve the above? I am looking for Pega OOTB features.