TWA 0001

TWA-0001

Message

"Expected port 443 to be open, but it isn't"

Explanation

The year is 20XX, and there is no reason for your website to not at least offer HTTPS access.

Without HTTPS, every other warning emitted by twa is completely moot: anybody sitting between your server and the end user can modify your traffic and neutralize your other protections.

Remediation

You can get a free TLS certificate from Let's Encrypt. Installing it is usually as easy as running Certbot.

If you don't control your web server, consider switching to a host that proves HTTPS out-of-the-box.