Dr. McKay

Only one Steam client session can be in-game at a time or else you get the LoggedInElsewhere error you mentioned. That guy isn't running CS2 on the same account twice; the real game instance must be logged in under a different account.
No.

Topic is irrelevant, I found the post where steam session is explained. Thank you

No.

Yeah that should work fine.

You need to enable the useAccessToken option or trades containing CS2 items won't appear.

Fixed with adding "useAccessToken": true to manager parameter list

I solved the problem, I was sending 2 verifications to the server

Using the GetPlayerBans endpoint is going to be your best bet. There's no event for it.

Either works, but using steamcommunity is "better" since it more closely mimics how the official mobile app works. steam-user just happens to work but may break at any time (though it's been working since 2FA came out, so seems pretty unlikely that it'll break).

Update to 2.11.5 and this should work properly. In previous versions it checks if the new value === the old value, which it would in this case since it's the same object reference.

If log on succeeds, you get a loggedOn event. Check the example scripts in the GitHub repo.

You'd want to call logOn for any error event, likely after a delay.

Catch the error event to prevent the crash, and call logOn again to kick off trying to connect.

Not at the moment.

It's not mentioned in the documentation, but you only get an eresult in the error event if a Steam connection can actually be established. If you don't have an eresult proeprty, you can assume there was a network issue.
Only you can properly decide the best course of action for your app, but if your network is down then yeah, probably all you can do is wait and retry until the network comes up.

https://steamerrors.com/5

You can use NetHook2 for this.

If you're using a custom storage engine, don't change the value of the dataDirectory option. If you set it to null, the storage property isn't initialized so you get that error attempting to read 'on' of undefined.
steam-tradeoffer-manager uses the same storage scheme as steam-user, but they don't share the same instance. You need to register your save and read events on your TradeOfferManager instance the same way you registered them on your SteamUser instance.

Decode the JWT and check the exp parameter, but be aware that tokens can be invalidated server-side at Valve's discretion, and nobody's sure exactly what makes that happen besides IP changes.

This is a known issue, see: https://github.com/DoctorMcKay/node-steamcommunity/issues/321
community.login isn't going to work until I can finish the v4 rewrite. Until then, you can either use steam-session or steam-user to get login cookies for use with steamcommunity.

TypeScript definitions for steam-tradeoffer-manager aren't maintained by me, so I can't really help you specifically. That said, you can probably suppress the error using (EResult.Revoked as number)

Don't do it that way, that's a very bad idea. Write the entire 64-bit number to the buffer.

Are you sure? This shouldn't be possible. Steam caches classid+instanceid pairs indefinitely. The description data should never change.
Not really, my best guess is that D just stands for "data". It very likely is a hash to prevent scraping.
It's been my experience that any [SM], A, D triplet will work forever to fetch item data.

Can't be done.

Fixed in 5.0.10