Steps:
The key point is that you upload *from your course*, not directly into the Hub.
1. On your Moodle site, go to: Site Administration >> Server >> Hubs
Add the MAJ Hub to your list of Hubs https://showcase.moodlejapan.org/
You will see a blank for a password, but you do not have to make a password.
2. Then go to the course you want to upload. Inside that course go to: Course Administration >> Publish
Click “Share this course for people to download”.
3. You will be asked which hub you want to publish to. Select the “Moodle Association of Japan Hub”
4. Fill in the metadata form (information form about your course).
5. Click upload and wait. It might take several hours or several minutes.