Ideally, a human being would make sure that a font package has the right homepage URL in its metainfo.xml file.

Failing that, however, the font handler can look for the "Vendor URL" entry in the fon't name table. That's the nameID 11 field.

It certainly isn't guaranteed to be specific to one font, but it is better than no URL.

( detail at https://docs.microsoft.com/en-gb/typography/opentype/spec/name#name-ids )