SteamTradeofferManager: Cannot obtain a session (access denied)

[GoKritz]

Failed to obtain API key.
Error: Access Denied
    at SteamCommunity.<anonymous> (/storage/tradingbot/node_modules/steamcommunity/components/webapi.js:15:20)
    at Request._callback (/storage/tradingbot/node_modules/steamcommunity/components/http.js:67:15)
    at Request.self.callback (/storage/tradingbot/node_modules/request/request.js:185:22)
    at Request.emit (node:events:390:28)
    at Request.<anonymous> (/storage/tradingbot/node_modules/request/request.js:1154:10)
    at Request.emit (node:events:390:28)
    at Gunzip.<anonymous> (/storage/tradingbot/node_modules/request/request.js:1076:12)
    at Object.onceWrapper (node:events:509:28)
    at Gunzip.emit (node:events:390:28)
    at endReadableNT (node:internal/streams/readable:1343:12)

SOURCE CODE: https://github.com/porkandbeans/tradingbot/blob/26ba3290cc0103cb37a17ba2c5b3bd5745fe25f8/bot.js#L109

I'm assuming SteamCommunity isn't supposed to be trying to get this data anonymously. What am I doing wrong here?

[GoKritz]

Update - I've discovered this error was because I did not have a Steam developer API key for my bot account. These are available when you have games on your steam account valued at or above $5 USD. After remedying, this error no longer appears.

However...

The newOffer event is still not firing for me and I am not sure why... how long do I typically have to wait after making purchases for this to work?

[Dr. McKay]

newOffer shouldn't take longer than 30 seconds. It should be pretty much instant if you passed a SteamUser instance to TradeOfferManager.

You might try outputting TradeOfferManager's debug output to see if anything is amiss:

_manager.on('debug', (msg) => {
    console.log(`[TradeOfferManager Debug] ${msg}`);
});