I have not used URP 2D, and I was going to respond with shader graph ideas, but it seems this is partly already supported?
2D light and shadow techniques in URP (unity.com)
The issue is the specular which I don’t see… But assuming shader graph for 2D works like 3D it’s probably a matter of just doing the usual 3D shader stuff? NdotL, GGX specular, etc.
I also found this thread.
Using Normal Maps with Custom Lit Shader and 2D lights - Unity Engine - Unity Discussions