Empty value for belongs_to field

[mbajur]

Hello!
I'm trying to modify model's form for rails_admin but i'm not able to implement not find any tutorial on one simple thing. Can i somehow add an empty option for belongs_to field?

Let's say i have two models - Shop and User. User belongs_to Shop. If i will use field :shop in User rails_admin config, it gives me a widget with all available shops but i'm not able to not select any of them. There always needs to be one selected.

Thanks in advance for any clues!

[mshibuya]

Actually this can be achieved by clearing out the search widget by repeatedly pressing the backspace key.
But I agree that it would be better to have a mouse-friendly way, like showing a ❌ button which clears the current selection.