You can use this Instagram Stories mockup made by Gil Peres in order to preview how your end result will look like.
Instagram Stories Mockup (Free PSD file)
A fully editable PSD mockup of the current Instagram Stories layout.
You’ll be able to change the number of stories (1 to 3), the user profile picture, type of story (sponsored or not sponsored), story creative (1080×1920), selection between CTA and Message module, and call to action copy (Sign up, Download, etc).
Author: Gil Peres