I don't have / or can't see "Combine and mask objects" option in my application.
I use Windows 10 64bit. Is the facility works only in Mac OS? if not tell me what should i to get the option on my app screen.
Unfortunately, this feature is not yet in the Windows app yet, though it's something we're working on for the near future! Please do upvote here to get an Email when we start the work, and another when we complete it.