Working holiday to 491

Hello! I haven’t seen a lot of information about this so any help would be greatly appreciated!!

I recently got invited to apply for the 491 visa (offshore). If my 491 visa is not granted before July, I am considering entering Australia on a Working Holiday visa in meantime.

Would I be required to leave Australia for the 491 visa to be activated, or would the grant be applied automatically while I am onshore? Thank you:)