Hey Inayat, checkout following code snippet to understand how to use Fluent Wait on a webpage or on a web element:
System.setProperty("webdriver.gecko.driver", "D:\\geckodriver.exe");
WebDriver driver = new FirefoxDriver();
driver.get("https://www.facebook.com");
WebElement notifications = driver.findElement(By.className("uiHeaderTitle"));
new WebDriverWait(driver, 10).
pollingEvery(2, TimeUnit.SECONDS).
withTimeout(10, TimeUnit.SECONDS).
until(ExpectedConditions.visibilityOf(stqatools));