Favicon is an icon that is shown in the browser address bar or tab when viewing your project. You can upload a favicon to your profile to display across all of your projects or create specific graphics for each of them.
A favicon can only be added to projects or profiles with a custom domain. You can use any static image as a favicon, but please keep in mind that it’s better to use images no bigger than 256x256px.
Set to the profile page. Open your profile settings and find the Public Profile section. Map a custom domain. After that, the favicon can be uploaded. Learn more about public profiles here.
Set to a project. Open the project settings and click the Domain tab. Map a custom domain. After that, the favicon can be uploaded.