Card validation issue for redirected domain


I wish to embed podcasts into my Twitter feed. This functionality works perfectly when I use the ‘original’ URL of my podcast which is: This works:

However, I own a domain ( which is used for the sole purpose of: and when I attempt to embed the same podcast using my own domain’s URL: the embed functionality does not work.

I understand that this issue is because my domain is not whitelisted for Twitter cards.

I have attempted to validate the card using and the response is:

INFO: Page fetched successfully
INFO: 2 metatags were found
ERROR: No card found (Card error)

Please advise what I need to do.

Thank you.