I need some help. I might have missed something.

The error message is quite clear, do you have a main-method with the specified signature in your Prompter class? If you do, please provide us the code so we might see what else could cause the issue.

import java.io.Console;

public class Prompter {
  private Game mGame;

  public Prompter(Game game) {
   mGame = game; 
  }

public boolean promptForGuess()  {
  Console  console = System.console();
  boolean isHit = false;
  boolean isValidGuess = false;
  while (! isValidGuess) {
   String guessAsString = console.readLine("Enter a letter:  ");
    try {
     isHit = mGame.applyGuess(guessAsString); 
     isValidGuess = true;

    } catch (IllegalArgumentException iae) {
     console.printf("%s. Please try again. \n", iae.getMessage());
    }
  }


  return isHit;
}

  public void displayProgress () {
    System.out.printf("Try to solve: %s\n", mGame.getCurrentProgress());
  }

}

This is what I have right now.

The error asks you to add a method like this:

public static void main(String[] args) { }

I am not familiar with this specific challenge so I do not know whether soemthing is supposed to be inside this method, but it has to exist nonetheless. The main method is the standard point of entry for your program.

Prompter.java:3: error: class, interface, or enum expected
public static void main(String[] args) {

Thats the error I'm getting now. I am assuming the code that I copied has to be inside those parameters. I still get this error though.

Your code does not have to (in fact, must not) be inside the main method. It is a method like the other ones you already have and must be located on the same level. For example, right after your constructor but before the promptForGuess()-method.

Can you link the challenge or video you are talking of? It will make it easier for others to help you.