Grass Detail shader Extending

Hello. I was trying to extend the terrain grass detail shaders. So I downloaded the built-in shaders for unity standard for version 2019.1.8. and added normal map support in the shader, yet when I select the grass on the terrain I can't see a field where I could put the normal map in.

So I was wondering what to do? I found no solution on how to extend the editor to make something like this work. Does anybody know what I should do?

 

Do u have the source for this shader ?

 

I do ofc. But it doesn't work if I can't apply the texture

 

ofc ?

 

As in offcourse I do.