Blizzard have introduced the WoW Token to Wrath Classic with this week’s reset. You can access it by going to the in-game shop (in the escape menu).

WoW Token (Source)

The WoW Token is now available in Wrath of the Lich King Classic™. This in-game item is a great way to exchange gold for game time in a convenient and secure way.

Please keep in mind that WoW Tokens cannot be transferred between World of Warcraft: Wrath of the Lich King Classic* and World of Warcraft. Certain restrictions apply. Visit our Support article for more details.

 

* Not available in World of Warcraft® Classic Era.