To progress to the next stage, you need to unlock it. You can unlock the next stage using three keys.
Getting Keys:
There are multiple ways to get keys.
1. A new key is added to your account every 9 hours.
2. Buy keys with jewels.
3. Request for keys from your friends.
Where are my keys?:
Keys that are sent to you are credited to your account when your friends send them, not when you check the message. The messages are there just for notification purposes to let you know when the lives were sent to you.
However, an account cannot have more than 3 keys. This means that if you are maxed out in the number of keys already, those sent by your friends cannot be credited to your account at that time.
However, an account cannot have more than 3 keys. This means that if you are maxed out in the number of keys already, those sent by your friends cannot be credited to your account at that time.
If you repeatedly request keys from the same friend, you will not receive additional keys. For example, if you request key from friend A at 11 o'clock and then at 12 o'clock, the amount of keys will remain the same even if your friend accepts your request.