This hook allows you to output content at the bottom of the PDF Tools Settings tab. Keep in mind our System Status notice uses this hook on priority 10, so you can choose to place your content before or after this block by changing your action's priority. Also, the Uninstaller has a priority of 5.
This snippet shows you how you can include a message after the Tools Settings form, but before the Uninstaller:
If you want to include content after the Uninstaller and before the System Status make sure your priority is between 5 and 10:
And to display content after the System status use a priority over 10:
This action is located in