Repeater addable

In the repeater there is an

addable

addable

function which you can use to decide if the user can add new items. It is possible to pass a closure. So I tried this:

            ->addable(fn (Get $get) => $get('../../sent'))

            ->addable(fn (Get $get) => $get('../../sent'))

However this returns null. When i log 'Get' I get a get object with in it the Repeater object. How can I actually obtain the value of the parent row?