There is also the option to import the ontologies (or any other ontology) via JSON files which we make available for download on this page. To generate these files we transferred the OBO versions of HPO and MONDO into JSON-format.

We currently provide two ontologies (use right-click + save as)

Within Zotero, you can then import these files into the library of their choice (as described here).

The obo2json converter is written in Java and is described here