Some scenes in the provided samples have the friendsTabUI.prefab included in them. This tab demonstrates the ability to query friends, send social invitations, and display social statuses.
When friends are queried outside of the Epic Social Overlay, only friends who have consented to the application will appear. This could mean that while testing a game with this plugin included, either none of or a subset of your friends may appear in the UI. See Epic's documentation on Friends List data privacy and Epic's documentation on Authorization and Consent Management for more information on this restriction.