Some sites have tried this before, but I dont think they stay online long. The certificates are "leaked" when they are shared, so the CA will revoke them. I th

Some sites have tried this before, but I dont think they stay online long. The certificates are "leaked" when they are shared, so the CA will revoke them. I think a better approach is to get a domain name and a Let's Encrypt certificate. There's lots of tooling for this, and it matches production. I built https://www.getlocalcert.net/ https://www.getlocalcert.net/ to act as free, Let's Encrypt compatible subdomain service specifically for these sorts of challenges.