Connecting to Plesk server you get a Your Connection is not Private message in your browser.
The Plesk admin area is secured by an SSL based connection (HTTPS) and out of the box uses a self-signed certificate. This will generate a warning in most browsers, stating that the certificate can't be verified. While this doesn't present a security risk, it can be disconcerting to some clients.
- When connecting to your Plesk server via your browser of choice via IP or host name you receive a "Your connection is not private" message.
Click on ADVANCED
- Click on Proceed to <IP> . It is safe to do so.
- Once you are logged into your Plesk server you can add a SSL certificate directly to Plesk.
Plesk 12.5 – How to secure Plesk Admin Login using Let's Encrypt
Plesk Onyx (17) You can use Security Advisor from your main Admin screen.