The app does not currently support gifting puzzle packs or Coins to another player.
However, you can buy an iTunes or Google Play gift certificate and give that to your friend to use to purchase puzzles or Coins.
Here is some documentation on how to redeem gift cards from Apple and Google Play:
Apple: https://support.apple.com/en-us/HT201209
Google Play: https://support.google.com/googleplay/answer/3422659?hl=en
As always, if Support can be of further assistance, please reach out to us and let us know via the Help and Support feature within the Game Settings.