This documentation is not using the current rendering mechanism and will be deleted by December 31st, 2020. The extension maintainer should switch to the new system. Details on how to use the rendering mechanism can be found here.
You have to create a PHP-File like our Example-File under Classes/Configuration/FlexForm/Example.php
You have to create a PHP-File like our Example-File under Classes/Configuration/Tca/Example.php
get FlexForm in ext_tables.php¶