Was it for "The Hero's Journey (full game)" or "The Hero's Journey (NSFW edition)"? The former would give you the files for this version of the game:
https://maneki-mushi.itch.io/theherosjourney
(this version doesn't have the NSFW content, but the purchase would have unlocked the booklet)
If it was the latter you would have been able to download the NSFW edition of the game, but not the booklet.