You need to locate the Munchkin ID for a specific Marketo instance.
What is a Munchkin ID?
How to find your Munchkin ID
1. Log into the specific Marketo Instance you need the Munchkin ID for. You can verify the instance name by checking the listing in the top left of your browser.
2. Go to Admin and click Munchkin in the tree on the left in the Integration section.
3. The Munchkin Account ID will be the first thing listed in the Tracking Code box.