Lives

In the game, (on my Android phone) tap the top middle where you you check to see how many of each type of boosters you have... there is a tab there called "Friends." Tap that tab. Then tap the little sign there that says "Add more friends." In the next screen tap "Invite friends"

This creates a link that you can send to real life friends or post in message boards, etc that when people tap, it opens the game and they are presented with a 'friend request envelope' for you.

Edit to add: Here's a request for me... https://ccs2.play.king.com/6Rar/Invite?id=12&params=%7B%22actionCode%22%3A%22246468231%22%2C%22coreUserId%22%3A%2211561415362%22%7D