The process is actually a bit complicated but let me explain it to you. Once you are on a dataset, click on the label that you want and use the slider at the top right corner of the page to switch modes (we call it smart detection). You should then be able to access three tabs and the errors are listed in the False Positive and False Negative tabs (I've added a screenshot in the blogpost so that you can make sure to be at the right place). Let me know if you have any problem, thanks!