Problem in Handling Authentication Popup Window

Question

I'm trying to handle authentication popup using Selenium Webdirve in Java. Here are the things I have tried :

1.  ```driver.switchTo().alert();
    //Selenium-WebDriver Java Code for entering Username & Password as below:
     driver.switchTo().alert().sendKeys("username" + Keys.TAB + "password");
     driver.switchTo().alert().accept();```
   

2. Using AutoIT :

    Send("username{TAB}myPassword{ENTER}")```
   
   
   
   

3. Selenium-WebDriver Java Code for entering Username & Password as below:

   driver.findElement(By.id("password")).sendKeys("myPassword");
   driver.switchTo().alert().accept();
   driver.switchTo().defaultContent();
   
   
   
   

I have used the above-mentioned methods but it doesn't work. Also , I am not getting any errors in console .