That would be the "no Focus" Focus: just don't turn on a Focus to allow all. Or, turn off the Focus you have turned on.
Focus is designed for blocking most or all Notifications. Block all, block all other than..., allow all but...
But, if need to have a Focus, will need to go under Apps and People under the Focus you want and change the options there to "Silence Notications From" and don't add any apps or people. And toggle on "Allow Time Sensitive".
Big problem is under Options. Silence Notifications option. It's Always or "While Locked", so will have some silencing.
So, better off just not use a Focus to allow all Notifications. Not gaining anything trying to use a Focus to allow all Notifications as that's an iPhones default mode.