Does querying composer packages via the Craftnet API need authentication? Ref https://docs.api.craftcms.com/packages.html
Querying the Craft CMS package itself is fine, eg https://api.craftcms.com/v1/package/craftcms/cms. However trying to query any plugins is throwing a 404, eg https://api.craftcms.com/v1/package/craftcms/contact-form