Hello, I am creating an environment and rendering it with karma. I create a shader in materiallibrary using principledshadercore. My problem is that I can't use the normals correctly, they don't give the right effect. Can you tell me how to use normals correctly in such cases?

You can't use triplanar mapping with normal maps without some custom implementation. normal maps require tangents, which don't exist when triplanar mapping, so it's not well defined even if you did come up with a custom shader that blended the resulting normals in object space. bump or displacement maps are preferred when using triplanar maps since they don't require any local tangent space to use.