how to create separate methods for function without effecting the code

public class GuessingNumber2 {
    public static void main(String[] args) {
        
        //game intro
        gameIntro();
        //random number initializer from 1 - 100
        randomNumberInitializer();
        //user input guess
        Scanner scanner = new Scanner(System.in);
        int attempts = 10;
        int start = 1;

        while (start <= 10) {
            int guessNum = scanner.nextInt();
            if (guessNum > randomNum) {
                System.out.println("Go lower!");
            } else if (guessNum < randomNum) {
                System.out.println("Go higher!");
            } else {
                System.out.println("You guessed it!");
            }
            start += 1;
        }
    }

    public static void gameIntro() {
        System.out.println("Welcome to the guessing game!\nGuess a number from 1 to 100!\nYou will have 10 attempts!");
    }
    
    public static void randomNumberInitializer() {
        Random random = new Random();
        int randomNum = random.nextInt(101);
        //from 1 - 100
        randomNum += 1;
    }
}

Hi I am trying to separate code into methods to make it look better and I came across a problem so once I have created a method randomNumberInitializer(), randomNum requires to be initialized so that it is seen by other code but if I initialize it with 0 then the whole game idea of random number creation comes to end, could you please help! I need randomNum to be created randomly by the game. Is there a way?