Question send and receive trade offer

[mnx_2016]

hi there ,

im make steam trade offer but i cant send and receive item

this is my code

manager.loadInventory(appid, contextid, true, function(err, inventory) {
	            if (err) {
	                console.log("ERR : "+err);
	                process.exit();
	            }

	            

	            console.log("Found " + inventory.length + " items");
	            /*var iteminventory = {
	                "assetid": offerid,
	                "appid": appid,
	                "contextid": contextid,
	                "amount" : 1
	            };*/

	            // Create and send the offer
	            var offer = manager.createOffer("https://steamcommunity.com/tradeoffer/new/?partner="+accountid+"&token="+token);
	            offer.addMyItems(iteminventories);
	            offer.addTheirItems(itemtheirinventories);
	            offer.setMessage("SENT  !");
	            offer.send(function(err, status) {
	                if (err) {
	                    console.log("ERR : " + err);
	                   
	                    process.exit();
	                }

	                if (status == 'pending') {
	                    // We need to confirm it
	                    console.log('Offer #${'+offer.id+'} sent, but requires confirmation');
	                    community.acceptConfirmationForObject("confirm code", offer.id, function(err) {
	                        if (err) {
	                            console.log("ERR : "+err);
	                            //process.exit();
	                        } else {
	                            console.log("Offer confirmed");
	                    
	                        }
	                    });
	                } else {
	                    console.log('Offer #${'+offer.id+'} sent successfully');
	
	                }
	            });
	        });

i getting error code 26

https://steamerrors.com/26

i know this error for item not exist but item id is exist in inventory .

best solution for my code

tnx

[Dr. McKay]

Clearly the item ID doesn't exist in the inventory.