The new Minecraft update that released RTX Shaders broke other shader texture packs, and I believe now you need an RTX card to turn on those RTX exclusive features, which I assume would turn on shaders. If this is intentional, then it's idiotic that you need and RTX card to use third party shaders, plus I believe you can only use these RTX shaders on a RTX enabled world. If this is a bug, please fix it.