[Wikibase] Getting started with federated Wikidata properties

Hi, I'm experimenting with a wikibase docker install. It's working fine, as far as I can tell. I can create Items.

I want to use federated Wikidata properties, as described here: https://doc.wikimedia.org/Wikibase/master/php/md_docs_components_repo-federa...

I've turned the function on in `LocalSettings.php`. When I try to add a statement, I can't seem to access any properties at all. What do I have to do? Do I have to request them using an API?

Thanks for your help, Will