My code won't loop

Use a while loop to keep asking the user to enter the order of numbers until the user does give two numbers in the right order (first smaller than second

Hi! i'm a beginner in java and I have this code but I can't loop the "error" message. it just prints 2 times

import java.util.Scanner;

public class Q6 {
    public static void main(String[] args) {
        int num1, num2;
        Scanner keyboard = new Scanner(System.in);
        System.out.print("Please type two numbers:");
        num1 = keyboard.nextInt();
        num2 = keyboard.nextInt();

        if (num1 < num2) {
            int counter = num1;
            while (counter <= num2) {
                System.out.print(counter + " ");
                counter = counter + 1;
            }
        } 
        else {
            System.out.println("Error: the first number must be smaller than the second");
            System.out.print("Please type two numbers: ");
            num1 = keyboard.nextInt();
            num2 = keyboard.nextInt();
        }
    }
}