I noticed that in a lot of sites, the ones that built the website added text to the "view site information" section of the address bar.
like in this example: https://yourkarma.com/
How to do it?
You are referring to the "Karma Mobility Inc [US]" part. This is obtained by their SSL certificate.
It is the same reason that they do have a httpS url. You can contact your webhost provider to obtain a ssl certificate yourself or do some research to find where you can get this.
Nobody add this "button" in the URL bar: it's the browser that <strong>always</strong> (at least chrome) put there that button.
Why in some sites the button is bigger and green? it's just because those sites are <strong>SSL certificated</strong> (you can see also they are
https and not just
http). Which means that they are <strong>encrypted</strong> and you can see the name of the company that has been certificated. If you want to know more about this button of chrome read this: https://support.google.com/chrome/answer/95617?hl=en
No SSL certification: http://stackoverflow.com
SSL certificated: https://www.google.com
They didnt add any text. The text you see in that section (Karma Mobility, Inc. [US]), comes from the SSL certificate that was used to sign the site.
You can get an SSL certiicate for your site if you run an SSL site. An SSL site starts with a https:// instead of an http://. Depending on the kind of certificate you get, your organisation name could appear in that section.
But be aware that SSL cetificates can be pricey. If you use shared hosting, you can ask your host how to go about it. If you host with platforms like Godaddy or Bluehost, they provide SSL certiicates purchase and install from their dashboards.
Note that there are about 5 diferent types of SSL certiicates. You will normally have your organisation name displayed like that on the user browser if you purchase the <strong>Organization Validation SSL Certiicate</strong>.
Hope this helps.