The two custom shaders I created are currently not interacting with each other

Using Unity’s Vertex & Fragment Shader (HLSL)
I created a water shader and a simple lighting shader.

First, let’s explain each of the two shaders:

  • Water shader
    A water shader was created using data provided by Unity called CameraDepthTexture, and simple vertex animation is implemented.
  • Lighting shader
    A very simple shader that contains a simple lighting formula and expresses colors in the Fragment shader.

When these two shaders are applied to an object and overlaid on top of each other,(the water shader is Plane and the light shader is Cube) I am not getting the results I want.

If the Cube’s shader is a Lit shader
When overlapping with the water shader, a coastline is created, and alpha blending is also applied.
If the Cube’s shader is a light shader I created, alpha is not applied even if the water shader has an alpha blend.
Shoreline effect, depth effect due to CameraDepthTexture in water shader is not visible visually. I don’t know why.

Does anyone know anything about this issue?