How to pass PostProcessRenderContext.source to a texture property?

Post-processing V2 Stack

Type some code:

Code (CSharp):

1. public override void Render(PostProcessRenderContext iContext)
2. {
3.     var sheet = iContext.propertySheets.Get(shader);
4.     sheet.properties.SetTexture("_SrcTex", iContext.source);
5. }

Get a error message:

Argument 2: cannot convert from 'UnityEngine.Rendering.RenderTargetIdentifier' to 'UnityEngine.Texture' (CS1503) [Assembly-CSharp]

It means cannot convert iContext.source to Texture Type.

With Legacy image effect We can pass source RenderTexture to a Texture property:

Code (CSharp):

1. void OnRenderImage(RenderTexture src, RenderTexture dest)
2. {
3.     material.SetTexture("_SrcTex", src);
4. }

We are using Post-processing V2 Stack currently. Legacy image effect has been deprecated.
How to pass iContext.source to a texture property?