@ayshah0206 I am assuming you are going through the CSA fundamentals course and the task is part of one of the lab exercises. The validation button can be found on CSA course on the Now learning portal itself. Sometimes it doesn't work if your sessions is expired. Try logging in again and see if it works.
Please see this video https://www.youtube.com/watch?v=eF_BTSOWyeg to know how the tasks can be validated.
