Where do I find my MSN API Key? (For Wordpress Plugin Transposh)

Hello,

for my Wordpress Plugin "Transposh" (automatic translation) I need to enter my "MSN API key" (I think the plugin author means "Bing API key").

I have signed up for Bing API and at https://datamarket.azure.com/account I can find the following (in English: Primary Account Key and Customer-ID):

Which one of that is the required "API Key"? If it's none of the above, where exactly do I find the API key and how does it look like?

Hope to hear from you soon. Any hints are highly appreciated.

Rgds, Jan