My card doesn't validate. What am I doing wrong?

[mattpusateri]

I’ve tried using Yoast SEO. I’ve tried adding the code manually into the header. Neither works…

For a few tries, oddly enough, I saw a working card with the photo… but then it went back to throwing “internal server error” messages… Or “fetch error”

What am I doing wrong?

Here’s the URL: http://www.flyingdogdigital.com/democracyawakens