There is no plugin just simple installation steps required. Here is all informatino step by step http://www.question2answer.org/wordpress.php
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.