Go to the Guild window by tapping on the icon in the bottom left-hand corner of the Main Menu. Then select the Friends tab and tap the Find Friends button. Enter a player's ID to find them and tap the Plus button near their name.

To send a friend request to a player from the recommended list, tap the Plus button near their name.

You can also invite friends to the game. Tap the Invite Friends button to send an invitation with a link to the game to your friends on social media.