SunriseM

If you started the confirmation correctly, offer should be accepted. Also is recommended that you use acceptConfirmationObject instead of starConfirmationChecker. You can read more about it in the steam-community wiki

Read this. Remember you need to have enabled time polling

Try with client.gamesPlayed(["Custom message", 440]);

https://www.w3schools.com/jsref/jsref_splice.asp

Are you logged in the bot steam account before the function is called?

You can use "split" to convert the string to array and get the part you want. Example:
client.on('friendOrChatMessage', (senderID, message) => { //Example Message: /bet 45 var arrmsg = message.split(" ") //arrmsg = ["/bet","45"] var userNumber = arrmsg[1] if (message.indexOf("/bet") == 0){ client.chatMessage(senderID, 'Your bet is: ' + userNumber); } });

You can use "split" to convert the string to array and get the part you want. Example:
client.on('friendOrChatMessage', (senderID, message) => { //Example Message: /bet 45 var arrmsg = message.split(" ") //arrmsg = ["/bet","45"] var userNumber = arrmsg[1] if (message.indexOf("/bet") == 0){ client.chatMessage(senderID, 'Your bet is: ' + userNumber); } }); You will have to add other things like be sure that input has /bet [number],  verify the number can be used, etc

Because match is used in Strings and items.descriptions is an array.
 
You can use find().
function matchDescription(description) { return description === 'my description match'; } (this is the 388th line) if (item.appid == "my app ID" && item.type.match("My match")) { if(item.descriptions.find(matchDescription)){ return } )

You should use a loop (for, foreach, while, etc) to iterate all the inventory callback, you can create an array called items, and in each iteration you push a object like this one:
var item = { "assetid": inventory[i].id, "name": inventory[i].market_hash_name } if you need to make an asynchronous operation with that info and know when all iterations are finished, you can use async module.