<div class="icon icon-insecure-site" jseval="updateIconClass(this.classList, iconclass)" jstcache="2"></div>
We saw a lock icon in webpage and when we inspect the page the above is seen and we are unable to find where this class come from.
<div class="icon icon-insecure-site" jseval="updateIconClas (this.classList, iconclass)" jstcache="2"></div>
It probably came from https://fontawesome.com/v5.15/icons
You will have to check your css file, there should be a link to fontawesome , maybe it's in lined, impossible to say without seeing the files.
Either in the head section you have something like this
<link rel="stylesheet" href="path/to/bootstrap/css/bootstrap.min.css">
This will give you access to all the classes.
To be sure, you need to check the head section of the html and find all css sheets and check there. It's also possible that's it's imported via Js or hardcoded to html.
Without seeing your files, it's impossible to say.