Submitting an rss feed/ appleconnect

This has been a problem for some people. You must have a payment method registered in Apple Music/iTunes: make sure your computer is authorised to play purchases (Apple Music or iTunes menu Account>Authorisations>Authorise this Computer). Then try logging in at https://podcastsconnect.apple.com

If this fails I would suggest reporting it Podcasts Support: iTunes Connect | Contact Us

If that fails the next step is to contact Apple Support: Support

Don't present this as a podcasting problem - they don't handle those and will refer you to Podcasts Support (or give you an inaccurate answer judging by some people's experience). Present the problem as being the inability to access Podcasts Support. It's also been suggested that getting them to look at your Apple ID may clear matters: do you have a Developer ID? Someone else found that his didn't work and when he created a normal ID it worked.

You may also find it helpful to look at Robert Walch's post here: can't add my podcast to podcast connect -… - Apple Community

Where are you hosting your podcast?

Libsyn just rolled out a feature where you can now submit to Apple Podcasts via Libsyn's UI if you do not have a validated Apple ID and can't get into Apple's podcasts connect. It is best if you submit directly to Apple if you can - but for those that are never able to validate your Apple ID - if you host with Libsyn you can now at least submit to Apple via your Libsyn UI without the Apple ID.