I'm using Liferay Developer Studio 3.8 and Liferay Portal Tomcat 7.3.1.
I was wondering how can I insert Font-Awesome icons in a portlet (portlet4SpringMVC with JSPX in a widget's page) generated through IDE neither theme generator nor Blade CLI.

When I insert Font-Awesome 4 icons, the icon does not show up.


When I insert Font-Awesome 3 icons, the icon shows up replicated:

I already activated Font-Awesome option in System Settings, as stated in this site https://help.liferay.com/hc/es/articles/360034474512-Using-Font-Awesome-and-Glyph-Icons-in-Your-Theme

This is the code that's being used to test Font-Awesome icons:

[code]'<div class="input-group col-md-4">
   <input class="form-control py-2" type="search" value="search" id="example-search-input">
      <span class="input-group-append">
          <button class="btn btn-outline-secondary" type="button">
              <i class="icon-search"></i>
           </button>
      </span>
</div>'