So, if you visit any website and it doesn’t have an SSL certificate installed, then you’ll tend to get this HTTPS Not Secure warning into your web browser. In other words, whenever you try to open a website through Google Chrome browser, it can be connected in two ways either HTTP (non-secure) or HTTPS (secure).
The apparent cause of getting “Not Secure” displayed on your browser is the website you’re visiting is not providing a secure and encrypted HTTPS connection.
