What do you need userid to use User Highlights List. You can find it by using UserID end point in finding Userid.

You only need to use instagram username for User Stories information.

If the user does not have active stories, it will return as stories not found, but since the user does not have stories, the request comes back like this.

For example:
instagram

Bad shortcode request:
https://www.instagram.com/instagram/

Correct shortcode request:
instagram