If you've landed on r4.sn-vgqsrnes.c.2mdn.net, you've likely found a broken back-end subdomain, not a real website. The domain has no owner listed in public records, no privacy policy, and no way to contact anyone behind it. The biggest red flag is the SSL certificate: it's not valid for this domain at all, so any data you send to it can't be trusted to arrive securely — or to arrive anywhere meaningful.
This appears to be an internal Google infrastructure subdomain (the URL structure gives that away), but it's not resolving to a working page. Instead you get a plain 404 error. There's no evidence this site ever served consumer-facing content. For a subdomain like this, the complete lack of transparency and working security is not a normal sign of legitimate operation. The safest move is to treat any link leading here as broken or misconfigured, and not engage with it at all.