It looks like you're requesting a guide for something called — but this appears to be either a typo, a garbled phrase, or a reference to an unofficial/custom mod (possibly related to Minecraft modding, given "forge" and version numbers like 1.12.2).
The Jenny Mod is compatible with Forge versions 1.12.2 and 1.9.0, allowing players to enjoy the mod's features on these popular Minecraft versions. To install the mod, users need to: jenny mod forge 1122v190jar nacharty na extra quality
If you proceed with a version of this mod from a source you trust, the standard installation for Forge 1.12.2 is: Mod Loader: Minecraft Forge 1.12.2 File Placement: file into the folder located in your %appdata%\.minecraft\ directory. "jenny mod forge 1122v190jar nacharty na extra quality"
Modding is an art. Be respectful of original creators, avoid redistributing modified .jar files, and always credit the developers. Now go enjoy Jenny Mod with extra quality – you’ve earned it. Final note: Modding is an art