Action Details
Requirements and how-to articles for Instagram's action:

paid action
Create a video ad to appear in between user's stories.

You need this to get it done:

Facebook Page
Instagram uses the same advertising tools as Facebook, so a Facebook page is required in order to use the Ads Manager.
Instagram Business Profile
In addition to a Facebook Page, an Instagram Business profile is also required in order to be able to run ads on Instagram.
File format: .mp4/.mov
Maximum file size: 4GB
Video length: 15 seconds by default, but users can take action to watch up to 60 seconds.
Dimensions: 1080 x 1920 pixels recommended (600 x 1067 pixels minimum)
Captions: Not available
Audio: Optional
Video codec: h.264/vp8
Audio codec: .aac/Vorbis
Target Audience
Choose the target audience for your ad (gender, age, location, interests, etc.)
Marketing Objective
The following objectives are compatible with Instagram Stories Video Ads:
App Installs
Lead Generation
Brand Awareness
Video Views
The link you wish to include in your ad (where you would like to send your audience to.)
Call to Action
The following calls to action are compatible with Instagram Stories Ads:
Apply Now
Book Now
Contact Us
Learn More
Get Showtimes
Get Quote
Request Time
See Menu
Shop Now
Sign Up
Watch More
Listen Now
Duration and Budget
Choose how long you want your ad to run and what your budget is.
Choose currency, enter payment details and pay.
Requirements missing or found errors? Report

How-To Articles
A list of useful links for you:

Instagram Business - Instagram Stories
How to make use of Instagram Stories and Stories Ads as a brand/business.
Facebook Ads guide - Instagram Stories Ads (Video)
Creative specs and technical requirements for Video Stories Ads on Instagram.
Link missing here or found errors? Improve How-Tos