The Kunena team has announce the arrival of Kunena 6.0.9.1 [K 6.0.9.1] which is now available for download as a native Joomla extension for J! 4.2.x. This version addresses most of the issues that were discovered in K 6.0 and issues discovered during the development stages of K 6.0.
This is for users to help other users, to discuss topics that are related to forum administration in general or problems in running Joomla. This is not the place to ask for Joomla support. If you want assistance with Joomla please ask at
forum.joomla.org
There is no "paypal order" button in Kunena and I don't know anything about the issues you seem to be having, sorry. Perhaps the people who developed this "button" may have some answers for you.
There is no functionality in the Kunena software to do this. Kunena (as you probably know) is a Joomla extension to allow you to run a web-based discussion forum on your site. Your question is a general "Joomla" question and you will probably get an answer faster if you ask your question at
forum.joomla.org
.