the downloaded Complementary Shaders.zip file directly into this folder. Do not extract the files .
Return to the game, select the shader from the list, and click . Download Complementary Shaders zip
Navigate to → Video Settings → Shader Packs (or "Shaders" in OptiFine). Click the Open Shader Pack Folder button. the downloaded Complementary Shaders
Shaders cannot run on "Vanilla" Minecraft alone; you need a loader to act as a bridge. select the shader from the list