Hi,
sorry for late reply, this is not possible natively, anyway you can add the button with a template override:
- Copy file from /components/com_jsn/views/list/default.php (table.php if you use table view) in /templates/your-theme-folder/html/com_jsn/list/default.php (table.php if you use table view)
- Edit the new file and add the button, some tip at
https://css-tricks.com/quick-tip-making-a-print-this-page-button/
NOTE: the layout of the printed page are managed by template.