Modifying normals in material

I’m trying to setup a material for some stylized rendering, and one thing I’d like to do is modify the normals in the material. I’m trying to point them towards the camera a little bit to flatten the lighting. I’m using a PixelNormalWS node to try and read the normal input, but it keeps giving me an invalid input error when I try to connect it to the normals. How can I read the normals, modify them by some value, and then set them back to the material?