To clarify: Instagram currently does not support the scheduling of stories (I know there are some hacky ways).
Some Instagram scheduling tools have the feature to schedule stories and notify you when the time to publish has come. These apps then send you a notification on the phone and by clicking it, the Instagram app opens on the story publishing page and the only thing I have to do is to click on the publish button.
I am wondering now, how can I do this on my own?
The idea would be to receive an image lets say on telegram which includes a link which then by clicking opens the IG app and inserts the image.