Add Normal Maps to the materials

Some materials have a special “Add Normal” socket visible in the Shader Editor where you can plug a custom normal map directly and combine it with the material normals:

You can also use this socket if you have a low poly object with a high poly normal map:

You have to plug your normal directly to the socket without a Normal Map node.
I will progressively add this add normal socket to the previous materials. All the new ones will already have it included.