What is "unsafe script" and how to remove the "shield" icon?

Question

Digital certificates

Hello.

I put SSL on the domain, and it shows me this.
And for some, this page immediately loads

Answer 1

A script or an image is loaded on your page via http, which is why you get such an error.
See through the Inspect page - network (Chrome developer tools) what exactly is loaded without https.

Answer 2

Whose certificate? Issued by?