Where can I get the plug-in logging?

I run this plug-in as the post-build action, while I get nothing from build console log saying webhook is triggered or something like that. Where can I get something?

Reproduce the plugin as a Jenkins post-build action and inspect the build console output while a webhook is triggered. Determine where logging is expected and what observable output would confirm the webhook action completed; the issue does not name any files or tests to start from.

Written by the indexing model from the issue text.