I cannot share a video to facebook in privat or planned. This would be very nice.
Due to recent changes in the way Facebook is working with third-party developers, direct upload of photos and videos from other businesses to Facebook personal pages is no longer supported.
From Facebook documentation:
The publish_actions permission will be deprecated. This permission granted apps access to publish posts to Facebook as the logged in user. Apps created from today onwards will not have access to this permission. Apps created before today that have been previously approved to request publish_actions can continue to do so until August 1, 2018. No further apps will be approved to use publish_actions via app review.
For now, you can save your video locally to your system and upload to Facebook directly.
Let us know if you have any additional questions.