Player Card Validation won't Render Player

[morganric]

I recently had my domain whitelisted for Twitter player cards.

However when I try to validate the card and generate a preview, the player does not render. Should I be passing a https url to an iframe containing the player or just the player?

here’s my card url -
http://www.readioapp.xyz/elon/one-twin-exercises-the-other-doesn-t

Hope somebody can help.

Rich