GET all items with item_type = inventory

GET all items with item_type = inventory

Hello,

I'm trying to get all items with item type = inventory. 
I need all stockitems. 
When I use the search criteria, this is not working. 

critMap = Map();
critMap.put("status","active");
critMap.put("item_type", "inventory")
//Get all stock data
resp = zoho.inventory.getRecords("Items", organizationID,critMap , "inventory");
items = resp.getJson("items");
info items;

Can you please help me ?