What is a HTTPS?

The secure version of a web address. The s means the connection is encrypted.

HTTPS is HTTP with encryption added by an SSL certificate. Browsers mark plain HTTP pages as Not secure, and Google ranks HTTPS pages higher.

If part of a page still loads over HTTP (an image, a script), the browser calls it mixed content and may hide the padlock. That often happens after moving a site to HTTPS without updating old links.

What to do

Type your address with http:// and check that it redirects to https://.
After a site move, run a mixed-content check or ask your web person to search and replace old http links.