Error: Undeclared identifier: 'OutputDebugString'

I use OutputDebugString in my D开发者_运维百科elphi Code, but I receive the error:

Error: Undeclared identifier: 'OutputDebugString'

Which package is this OutputDebugString in?

It's declared in the Windows unit.

In windows unit in Winapi namespace:

uses
   Winapi.Windows;

How to find the unit of a specific command:

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