AdButler has a range of helpful documentation that can be found here, https://www.adbutler.com/help/guides

Step 1:

Create your AdButler account using this link www.adbutler.com.

Note: you may create a trial account, but this will limit your functionality.

Step 2:

This video gives a quick overview of some basic training of AdButler, https://www.youtube.com/watch?v=uKIiKVbZXkA

Step 3:

Set up your server breakdown. You can add content/ads as you want.

Step 4:

Follow the AdButler guide to generate a VAST ad item/link

https://www.adbutler.com/help/article/creating-a-vast-ad-item

Note: Video files uploaded to AdButler cannot exceed 50MB