Unable to open CreateAction in modal?

I have a resource where I created a CreateResource page but would still like to use a modal as the header action on the resource list page. For some reason the documentation seems to imply it's as simple as:

    protected function getHeaderActions(): array
    {
        return [
            Filament\Actions\CreateAction::make()
                        ->modal(true)


        ];
    }

But clicking this it redirects to the create page. I tried all kinds of things including trying to set a form schema and custom actions but nothing seems to work, all of it is ignored and it simply generates a redirect to the create page.

Any idea what I'm doing wrong? Or is it not possible to use a modal if you create a create page for the resource? If I remote the 'create' page from the resource itself it opens in a modal just fine.