Hi! Could you kindly clarify the bundle that you may have participated in Humble Bundle? If it's the latest bundle (Tiny Tales Treasure Trove), then the HB library should already provide you with a link to claim this product here on itch.io
If its any older deals, then we're afraid the new product isn't available for those, as they didn't have the product key options. We apologize for the inconvenience in that case.