You receive a Steam key if you purchase the PC/Mac version of the game on the website or You can claim this key on your download page. You should have a link to that page in the email that you received from after purchasing the game. If you need that email sent again, go here: 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 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 version of the game, and you registered that purchase with your WolfQuest game account, then that DLC will be unlocked if you switch to the Steam version of the game. (But this does not work the other way: If you purchase the DLC on Steam, then switch back to the itchio version, the DLC will not be unlocked.)