How to Force HTTPS for a Plesk Website
Plesk · Self-help guide
After installing an SSL/TLS certificate, you may want visitors to always use the secure HTTPS version of the site. In Plesk, open Websites & Domains, select the domain, and check the hosting or SSL/TLS settings for an HTTPS redirect option. Enable the redirect only after confirming the certificate is valid for the domain. Test by opening http://yourdomain.co.uk and confirming the browser redirects to https://yourdomain.co.uk. If the site shows mixed content warnings, WordPress, images, scripts, or styles may still reference HTTP links. Clear any website cache after changes. If the site becomes unavailable after enabling a redirect, disable the setting and contact support with the affected domain.