How do I stop default uploading of media with card additions or movement of photos

I have a deck uploaded on Ankihub (step 1 pixorized) and I am keeping all images offline. I have a separate location for media files where users can get those files.

If I add an already used image file, say <img=xyz.png> used on card 1, and copy that image to another card so <img=xyz.png> is now also used on card 2, ankihub will upload that image when synced.

Example:

I don’t want anything to upload to Ankihub for any media I add or update. Is there a way to completely stop media from updating?

This is a copy of an image file from another card, so users wouldn’t need to redownload anything as it would call from the media image folder.

This also happens if I make a copy of a card with Ctrl-Alt-E (to keep all the media / format / tagging) and change the text.

I don’t want Ankihub to upload the media at all. How can I lock this?

Any suggestions?