I think there must be a way, because it is possible to do so in Card Table (https://card-table.app/)
Viewing post in Using private decks from Marvelcdb
Hi @quantumodo,
Thank you for bringing this to our attention! We weren’t aware of Card Table before, and it looks like a great app.
After testing their code, we found an API that allows access to “private” decks, but it requires users to enable the “Share your decks” option in their settings.
We will consider adding this feature in the next version.