how to find steam id number.

[YEAHHHBUD DIMIK]

trying to join DTK and it says this.
You did not enter the correct format for the Steam ID field. Please read the field description for the expected format.
A required field called Steam ID is missing or has an invalid value.

[Seriox]

You can find your steam id by using the command status in your console or here[steamid.io].

[Max]

Hey,

There are a few different types/formats of SteamIDs.

These are the different representations of your account's SteamID:

• SteamID32: STEAM_0:1:184754215
  
• SteamID64: 76561198329774159
  
• Steam3ID: [U:1:369508431]

The SteamID32 is most commonly used in Source games, for example to assign server permissions; this ID is probably what you're looking for in this specific case.

[MOCOLONI]

Although Max has already posted all of your valid ID's (SteamID and Community ID), I'd like to note that you can also create a singleplayer server, open the console, and submit "status" so it will print all the information of that server, including the map's name, the amount of players (and max. allowed players), active players (their nicknames), and their respective Steam ID next to the names.