You receive a Steam key if you purchase the PC/Mac version of the game on the WolfQuest.org website or itch.io. You can claim this key on your itch.io download page. You should have a link to that page in the email that you received from itch.io after purchasing the game. If you need that email sent again, go here: itchio.io support.
  1. Go here for the Steam version WolfQuest on Steam
  2. Click the 'Install Steam' button at the top of the page, then register an account.
  3. Then go back to your itch.io game download page and claim your Steam key.
  4. In the Steam app, go to your Library and click Add a Game in the bottom left of the window and choose 'Activate a Product on Steam' and paste that Steam key.

Then, if you previously created a user account in the game, then click the 'Pull Files from Server button' after the game starts up. That will sync all your game data on the new computer.
 
Please note: If you purchased any DLC from the itch.io version of the game, that DLC will not be unlocked on the Steam version of the game. DLC purchases are tied to the version you were playing when you made the purchase.