2

If the data-type is a list you need to wrap it in single brackets: [“item1”, “item2”].
You cant do that twice like you do, so this is not valid: [“item 1, item 2”], [“item3”, “item4”]

So basically it would like like below:

{
    "Category_Single": "This is a category",
    "Category_List": ["category_1", "category_2"],
    "Item_Single": "This is an item",
    "Item_List": ["FirstSearch", "SecondSearch"]
}

Be aware that if your are referencing and item, say you have a product type of “apple” that you reference in your list, that item needs to exist, otherwise your post request will fail. You then need to reference the full id.

  {
        "Category_List": ["category_1", "category_2"],
        "Item_List_referenced": ["12345x54321", "422313x435252"]
  }

Etc.

Hope that helps
Simon