A favicon is the small image that appears in a browser's tab for a website. Adding one helps with your branding and makes it easier for visitors to find your site among all their open tabs.
Click Design at the top of your Websites app to open the design panel.
On the right-hand sidebar, select the Sitewide tab.
Click Header & Logo.
Scroll down to Favicon. You can either drag your favicon file into the box or click to upload it.
Note: Your favicon must be a PNG file between 256 and 512 pixels on each side. Transparency is allowed.
Click Save, then Publish to make your favicon live on your website.