If your PC is using integrated graphics instead of GPU, first of all, check all your cables, force programs to use dedicated GPU, and check this post.

It is best to use a GPU when playing a game or doing video editing. However, integrated graphics on your CPU will still work in a pinch.

Here is a step-by-step comprehensive guide on how you can download, install, and use the shaders within Minecraft 1.21.5 to ensure the best visual experience.