I am not sure if this works:
* Download
Onyx Boox Note v3.3.2 firmware (You may need to copy the link, open another browser tab and paste the link), the download filename should be update.upx
* Place update.upx file in the root folder of your Onyx Boox Note
*
Just follow this guide to update
Please keep the update.upx file in case this method doesn't work for you.