The process of adding SSL to a web site requires a few steps.
Contact your web host and ask for their help as they will have their own method of adding SSL to a web site.
This is what I usually do with my clients or my own WordPress web sites.
– Check in with the web host in regards to the process to setup SSL.
– Login to the WordPress site and go to the backend. Then to Settings -> General then change the address:
WordPress Address (URL) and Site Address (URL) from http:// to https://
One will then have to login to the site again. Clear the cache to see the new result.
– Install the WordPress plugin Better Search Replace to locate the leftovers of http.
Search for http:// and replace it with https:// . Select all the tables listed. Do a dry run first then uncheck the dry run to replace all the instances of http:// with https:// .
If the site is still not secure with mixed content then check the site here:
An example. The site I tested used the plugin Smush to make images smaller. 3 images were not added http to, so I deactivated Smush and used Better Search and Replace to see if the 3 images would be found. They were and I adjusted them from http to https. I then reactivated the Smush plugin again. Checked the front page and noticed the green padlock. I then also checked the site again with whynopadlock.com. This time the site had become secure.
A few more detailed resources:
An example to add SSL can be through cPanel: archhosting.net/wiki/SSL_Certificate