twitter:card App doesn´t work

Dear all,

I implemented JM Twitter Cards because it should be support twitter:card App. I did all settings and used Application as card type.
Additional to that i use Yoast SEO Plugin but enabled the Twitter Markup, so they can´t mess up.
However the tag for twitter:card is not using application. It still is using this Tag I won´t have.
name=”twitter:card” content=”summary”>
It´s about this website:
http://www.chefkoch-app.de/

Any idea why this doesn´t work?
Can it be that because I have to reference the orginal site means http://www.chefkoch.de. So means it does not work for other sites who reference the app?

Thanks for replay.

https://wordpress.org/plugins/jm-twitter-cards/