If your version did not come with OptiFine bundled, download the 1.12.2 version of OptiFine and place it in the .minecraft/libraries or mods folder created by Wurst. Safety Warning
Get the .jar file for v6.35 from the link above. Download Wurst v6.35 MC1.12 OF
Includes built-in support for OptiFine (OF), which can be added manually to the mods folder or is sometimes bundled in the installer depending on the specific "OF" edition. Installation Steps If your version did not come with OptiFine
Only download Minecraft clients from official sources like WurstClient.net. Downloading from third-party "re-upload" sites or YouTube description links can expose your computer to malware or account theft. How to Install Minecraft Hacked Client for 1.12.2 - Wurst Download Wurst v6.35 MC1.12 OF