No Worries it's Easy!
First select your Mac OSX Preset on the Left of the Export Window. Now on the Right select the Options tab, and scroll to the very top. You should be able to see a Custom Templates section and an Application section. Ignore the Custom Templates, and look to the fourth entry under Application, it should say Identifier. Fill in the Identifier field however you like. Usually com.username.projectname. So com.skulltip.project would work.
Second, disable Notarization by scrolling all the way to the bottom of the Options tab, and unchecking the box Enable under Notarization. You don't really need to notarize unless you're planning on publishing to the Apple App Store, which usually requires a Mac Device, and $100 yearly subscription.