Run the .jar installer you downloaded. Select version 1.19.x , choose the "Iris + Sodium" install type, and click Install .
The classic choice. Download the 1.19.x version from the official OptiFine site . 2. Install the Loader
Offers much better FPS on modern versions like 1.19. Download from the Iris Shaders website .
Open the and select your new Iris or OptiFine profile.