Firstly, you'll need to sign up to be a Content Provider for Stitcher. You can do this by heading to this link: https://www.stitcher.com/content-providers
Fill in your details in the form at the bottom of the page and click Continue. This will finalise your application.
Once you have become a Content Provider, you will be able to log in and click Add Shows in the top bar if you don't immediately get taken to the Submission Form. The form should look like this:
Fill in your details and remember to accept the Terms and Conditions. Then, click Continue.
Follow everything through and your show will be submitted! Stitcher will send you a confirmation email once your show is live along with a link so you can find your show easily in their directory!