How to create Authority files?

Yes, you have to create an adapter, see https://wiss-ki.eu/documentation/authority-files - in the beginning:
CONFIGURATION
Add adapters

:)

Cheers

@Knurg Thank you! Are Geonames and DNB GND the very Authority files? If so, what does the module wisski_authfile do? Very confused by the module name.

We have generic support for anything that can be imported via SKOS and several specific authority file adapters that draw information directly from the authority file provider like GND and Geonames :)

So it depends on what you want to do! I would need more information about that to be more specific and point you to the correct direction :)

Cheers!