From the Ajax handler method
echo json_encode($res_date_arr, JSON_UNESCAPED_UNICODE);
Got a string of the form
["20190425","Digital Lab as part of the digital transformation of the oil and gas companies","http:\/\/name.ru\/wp-content\/uploads\/2019\/04\/digital_lab.jpg","25 APR 2019","16:15","DK Foyer\"Fedorova\"","","","h...