Setting up a favicon on your website is not as easy as you might think.
But you can do this using Favicon by RealFaviconGenerator
wordpress plugin.
Favicon by RealFaviconGenerator
WordPress PluginSearch 'Favicon by RealfaviconGenerator' in [Plugins] -> [Add New] page and install it.
Go to [Appearance] -> [Favicon] page and select logo which you want to ganerate as a favicon.
Click Generate favicon
button to start generate. You will be redirected to generation page.
Choose options which you want to apply, and click Generate your Favicons and HTML Code
button on the bottom to apply it.
You will be comeback to your website, and you will see the favicon in your browser.