Numismatic vocabulary

I am trying to import a vocabulary for describing coins. I’ve tried to use the RDF and TTL files that are made available here: nomisma.org: Ontology

Can someone please help with this?

This worked for me:

Label: Nomisma Ontology
Namespace URI: http://nomisma.org/ontology#
Namespace prefix: nmo

Vocabulary URL: http://nomisma.org/ontology/210715.rdf
File format: [Autodetect]

Wow. Thanks. I think I had the namespace prefix wrong.