You can use beta form by GitHub/Microsoft: (https://github.com/FiltersHeroes/KAD/security/advisories/new)

Optionally you can still send via e-mail address found at page: https://kadantiscam.netlify.app/#contact - web form at bottom of page almost immediately open public issue - Absolutely do not enter a bug report there that violates the security of i.e. a repository!