Path of the selected material's texture

Dear community!

I am a bit lost in the documentation. How do I get the path of a selected Material's texture into a variable?

I made this so far:

 using UnityEngine;
 using UnityEditor;
 using UnityEditor.VersionControl;
 using System.Collections;
 
 [ExecuteInEditMode]
 public class MaterialAssigner : Editor
 {
     public string sDiff;
     private Texture textureValue;
     private Texture tDiff;
     
     [MenuItem( "MyMenu/Selected Texture")]
     
     public static void MySelectedTexture()
     {        
         tDiff = MaterialEditor.GetMaterialProperty(targets, "_MainTex").textureValue;
         sDiff = tDiff.name;
         Debug.Log(sDiff);
     }
     
 }

But it says

 error CS1502: The best overloaded method match for `UnityEditor.MaterialEditor.GetMaterialProperty(UnityEngine.Object[], string)' has some invalid arguments

and

 error CS0120: An object reference is required to access non-static member `UnityEditor.Editor.targets'

and

 error CS0120: An object reference is required to access non-static member `MaterialAssigner.tDiff'

and

 error CS0120: An object reference is required to access non-static member `MaterialAssigner.sDiff'

But without the STATIC in the 15th line, it not making a Menu. Then how I execute it in the Editor?