This is the code i wrote to read the text of paytm login window and close the login window

am unable to identify the close button of the login window (its showing as image instead of button)

can you please help in this

public static void main(String[] args) {

System.setProperty("webdriver.chrome.driver", "C:\\SeleniumLearning\\Browsers\\chromedriver_win32\\chromedriver.exe");
WebDriver driver=new ChromeDriver();
driver.get("http://paytm.com");
driver.manage().timeouts().implicitlyWait(20, TimeUnit.SECONDS);
driver.findElement(By.xpath("//div[@class='_3fM-']")).click();
List<WebElement> frames=driver.findElements(By.tagName("iframe"));
System.out.println("Total frames inside webpage is "+frames.size());
driver.switchTo().frame(0);
String text=driver.findElement(By.xpath("//div[@class='content']")).getText();
System.out.println(text);

// trying to close the login window 
driver.findElement(By.xpath("//*[@id='\"app\"]/div/div[1]/div[3]/div[2]/div/a/img'")).click();
driver.switchTo().defaultContent();

}