Aha! I see, it shows data based on POST request from FORM on this page http://www.dsden93.ac-creteil.fr/spip/spip.php?page=annu1d so if you provide just a link to the results page without the POST data then it will show you nothing. Sadly the tool currently does not allow for sending POST requests to the websites.
[ 0:{ "selector":".bloc-blanc > p:nth-child(1)" "text":" 0 école(s) correspondent à votre recherche " } ]