Before you actually submit your feed to iTunes, please check your podcast to ensure that you have followed all requirements needed.
1. Change your Cover Art Image (Max image size 400kb, 1600x1600 JPG or PNG)
2. Upload at least one podcast episode (try to compress your file, for example use a Mp3 format)
Before submitting your RSS feed, you'll need to make sure it's valid. Here is a list of free RSS Feed validators:
You must have an active Apple ID to submit podcasts to the iTunes Store Apple Podcasts directory. You may create a new Apple ID if you do not already have one.
2. Click the iTunes Connect Add podcast button at the top left of the iTunes Connect dashboard.
3. Enter your RSS feed into the provided text box and then click the “Validate” button.
4. A Feed Preview will load if you do not have any validation errors. Please take a moment and review your podcast artwork, description, general information (e.g. description, categories, etc), and episodes. Please see the Validation Errors section if you have any problems validating your podcast feed.
5 If everything within the Feed Preview is correct, click the “Submit” button.
For more information, please visit: https://itunespartner.apple.com/podcasts/articles/submitting-your-show_submission