*This text is applicable to Chromium browsers.
Click anywhere on the website to bring the page to the top layer.
Switch to English and enter the following characters anywhere on the webpage (make sure the spelling is correct):
You will then be able to access the website.
(After refreshing, this warning will not appear. You can click the address bar's
button and enable the warning ↓
HSTS stands for HTTP Strict Transport Security. It is a method used by websites to declare that they can only be accessed through secure connections (HTTPS). If a website declares an HSTS policy, the browser must reject all HTTP connections and prevent the user from accepting insecure SSL certificates. Currently, most mainstream browsers support HSTS (except for some mobile browsers). (From source)
The website has enabled HSTS, which means it can only be accessed through HTTPS. However, if there is an issue with its SSL certificate and it cannot be accessed through HTTPS, the browser will automatically reject the HTTP connection, resulting in the website being inaccessible.
"this is unsafe" is a built-in backdoor in Chromium-based browsers that allows bypassing the aforementioned security checks to access the webpage. The name also serves as a reminder for users not to misuse it (previous versions were named "badidea").