Since July 2018, Google began to prioritise website which have an “SSL” cert (Secure Socket Layer) and to punish website without an SSL cert by adding “ NOT secure. “ to their website address..
You may have noticed that beside the address bar there is an info icon, and has the word “Not Secure” – if you have an SSL cert it displays a green padlock and is marked as a secure connection.
See screen shots attached for your reference.
An SSL cert basically encrypts the communication between the website and the browser (e.g. Chrome) so that it can protect your website visitors and stop website hacking.
It has become industry standard protection world wide is is used by all browsers now, google has taken it one step further and now priorities results which have a valid SSL cert.
Let me know if you would be interested in adding one to your site.