It's important to make sure your site has a favicon. This is the small image that appears on each tab and helps to brand and identify the site to users when they have many tabs open. The way to do this was via the customiser.
As we're building a Seed site, you can use the favicon for your seed site which you should have already uploaded to the media library.
The customiser may be removed from the WordPress dashboard. Normally we would place the favicon, by visiting Dashboard → Appearance → Customize → Site Identity and clicking on the select site icon button.
NOTE!
If the customiser does not exist for you, you can arrive at the same place by visiting a URL like this : https://yourdomain.com/wp-admin/customize.php
Obviously change yourdomain.com to be the domain you are working with.
Once you get there you can select your favicon file from the media library As your favicon should already be square, you can skip cropping.