A favicon can be set in the Site Settings for your site. It will apply to all pages of your site.
Prepare a Favicon File
Save an image in PNG format, sized 32px X 32px square.
A quick tool is available at Favikon.com
Add Your Favicon to Showit
Open your site design and in the site panel (left) go to Site tab > Site Settings
Find the Favicon setting and click Choose Image
3. Upload your favicon file (bottom left) and select it
4. You'll see a preview of how it may appear in the browser.
5. Publish to see the change online.
Things to Know
Not every browser will display the favicon at all times
It may take 24 hours to fully update across web browsers who have already visited your site recently.