It should be noted that many websites do not provide all the information that citation styles want, or the information is not on the page you view, but someplace else within the website. Your instructors do expect make an effort to see if you can find the missing citation information.
An easy way to see if all information was included is to look hit the Edit button under the citation that was generated. If there are any blanks, then you know that some of the information was not retrieved. Frequently this will be author, date published or publisher. Check the site to double check. If you find it you can just add while in edit mode and hit the Done button.