Also known as a Favicon, WordPress has this as part of your website’s customization. Normally, this is a good tutorial for learning the WordPress dashboard, but we believe this adds to the theme setup process to enhance your visitors’ experience.

Prepare your favicon image file by making it square and at least 512 pixels for the width and height. We recommend using an image format of PNG or JPG for best results.
To upload your own site icon, go to Appearance > Customize > Site Identity
- Click the Select Image button at Site Icon section to upload your image file.
- Click the Publish button.