First, launch the software on your Windows PC. Once downloaded, the first screen of the software will be shown as:
Now click on Add Files and "Add Folders" to upload multiple OneNote files as per your requirement.
The software will display the list of added OneNote, as shown below
You can even delete any unnecessary OneNote file using Remove File(s) button. Or you can even delete all OneNote files and clear the software screen using Remove All button.
select required output option to convert OneNote files into multiple file formats
Choose the saving path for saving output data. and hit the Export button.