Hello! If you buy the DLC files anywhere, they should work on any version of the base game, itch or Steam. However, if you need help specifically with Beginnings & Always, please feel free to post over there! Here's the link to the base game's page, and I'll see you over there as well:
https://gbpatch.itch.io/our-life
Thank you for playing! We hope you enjoy the game.
