The best way to get your list out of To Do is either by printing it, or emailing it. You can do this by tapping or clicking the list name, then Settings > Actions.
If you'd prefer a CSV copy of your tasks, you can connect your list to Zenkit Base and export it as a CSV from there.
If you're able to, another option would be to use the API directly or export as CSV or PDF via the API. You can find our API documentation here: https://zenkit.com/docs/api
A JSON export is in the works and will be ready in the near future.