Spatie Media Library outside a Resource

I'm using this field on a Filament Form added to a Livewire component.

I can't seem to find a way to provide the Model for where to attach the media.

Did I miss it?

In the docs, I understand there's something to be done. I follow the link and find nothing about relationships. Wrong link, or missing piece maybe?

https://filamentphp.com/plugins/filament-spatie-media-library