The Help / About screen provides a list of supported file formats.
It does not list Onenote (.one) files.
However onenote appears to be supported, since at least some of the content of my onenote files appears?
I found this evaluating the product for possible use, so I have no idea what other formats may be missing from the list, or if one note works reliably, but you might want to update the list if it does. I nearly gave up the product based upon the Help screen.
Cheers! Thanks for making your product available, it clearly has taken a lot of effort to develop and support.