Thanks for your advice.I get the $_POST variable result. I found out that other than topicId,draft_id field, other field name is generated dynamically0__CSRFToken__c88bc0b52fba4d87fb626b0b0916|a|topicId|9e335eadfa024bf3@test.com|ed354e776a882c29|74313c790720574b:|74313c790720574b-ext:|3104608c16d241d6t|message|5224a3bae55eb589:|draft_id|form010I want to get the email address input from user in create ticket form.