You're referring to the "De Fapcraft" mod for Minecraft 1.12.2!
De Fapcraft 1.12.2-v1.1.jar is a... unique mod that adds mature-themed content to Minecraft. If you're an adult player interested in exploring this type of content, make sure to follow the installation guide and in-game tips. Happy crafting!
That being said, here's a guide to help you get started with the De Fapcraft 1.12.2-v1.1.jar mod: