To get the friends' data, do as in the code snippet below:
[SerializeField]
SteamFriendsList steamFriendsList;
IEnumerator AsyncGetFriendsList()
{
List<SteamFriendEntry> friends = steamFriendsList.GetFriends(true);
// Wait a while for the avatar images to load or ignore this line
// if you only want to get the names of the player's friends
yield return new WaitForSeconds(1.5f);
foreach (SteamFriendEntry steamFriend in friends)
{
// Do what your imagination tells you
}
}
An advanced working example of the Friends List module can be found at Assets > Lucky Raccoon Games > Really Simple Steam Integration > Demo > 04 Friends List