org.openqa.selenium.NoSuchElementException: Returned node (null) was not a DOM element when trying to locate card-fields-iframe by CssSelector

Question

I am trying to locate an iframe by partial id. For this method, I used: driver.switchTo().frame(driver.findElement(By.cssSelector(\"iframe[id*=\'card-fields-number\']

Answer 1

As the iframe has tag iframe, you can switch to the iframe using the tagname like:
driver.switchTo().frame(driver.findElement(By.tagName("iframe")));
And if you want to again switch to the default content, then you can use driver.switchTo().defaultContent();