In Wikidata, external identifier properties can have an associated "formatter URL" that will allow Wikidata to format a URL for the property value based on the identifier, e.g., https://www.wikidata.org/wiki/Property:P10831 has set the https://www.wikidata.org/wiki/Property:P1630 with "https://ordregister.dk/id/$1" which means that any item that use P10831 will get a URL, e.g., "COR.38799" with P10831 will be linked as https://ordregister.dk/id/COR.38799
I have tried a similar method on a cloud-based Wikibase, https://dreams.wikibase.cloud, but no link appears. For instance, an external identifier property https://dreams.wikibase.cloud/wiki/Property:P40 has the property https://dreams.wikibase.cloud/wiki/Property:P4 set to "https://daieproddreamspdfsto.blob.core.windows.net/files/$1", but items using P40 do not display a link.
Is it possible to make external identifier value links? Where is the option?