Update 'VRAPoten-API.md'

VRAPoten-API.md

@@ -78,6 +78,8 @@ Response 404 Item not found
 ##### Optional input parameters #####
 There are some optional task attribute input parameters for greater flexibility.
 
+* **inputLayerName**  
+ * Allows you to specify which layer to use for an input item.
 * **countPerArea**  
  * Allows you to specify if spacing in cm needs to be calculated to count per area in m2.
 * **useShadow**
@@ -87,6 +89,7 @@ defaults are false
 
 ```javascript
 {
+    "inputLayerName": "EC_30",
     "countPerArea": true,
     "useShadow": true
 }