LinkedIn is the worst. Starting a trial through the mobile app requires only a couple of clicks. Trying to cancel that trial? Haha! Good luck! There's no way to do it through the mobile app. I had to open the website, login there as well, go to the help section, search for "cancel" and click on the help article. At this point I was greeted by "this feature is not supported on mobile devices" so I had Firefox request the desktop version in order to view the page.