When you level up in the event, you will see new rewards available in the 'Rewards' list. Tap to claim any that you have unlocked. There are several types of reward available:

Coins and Tokens are added immediately.

Frames, Bombs and Coaches can be activated when you start or restart a puzzle. Under the puzzle, you’ll see buttons to activate them, and a number showing how many are available.

Free Puzzles are unlocked in the event pack. From the game’s main menu, select the star icon at the bottom of the screen to view event packs. Open the current pack to play any puzzles that you’ve unlocked.

Free Play Time begins immediately. You’ll be able to unlock puzzles without paying any coin or token cost. Unlock a puzzle for free, complete it and repeat until the time runs out. You can use this in any pack, except for the current event pack (because these puzzles can be unlocked for free through other rewards).

Spins allow you to spin the wheel and win one of the prizes shown.

Remember to claim all your rewards before the event ends!