API Feature in Viva Connections not availabe

The new API Feature in Viva Connections is not available in Viva Cards. 

I do all the settings like described in this video 1 week before but nothing is changing in the Card Designer.

https://techcommunity.microsoft.com/t5/viva-connections-blog/introduction-to-new-advance-api-features-in-viva-connections/ba-p/4007954

Are settings are done:

Is there a additional setting needed to be set, to use the API Feature?

Thank you!

Sabine