With this application you can find the icon you are looking for among the more than 3000 that are registered. Each of them includes the code that you must use to integrate it and the font to which it belongs. All fonts can be found free on the net and are free for general use.
It includes a practical search engine that will help you find just the icon you are looking for.
As a developer, remember that it is more memory-efficient to use a font than the images it contains.