Hi Gabriel,
just wanted to point out that there's a dedicated space here on SCN for Cloud for Customer, too:
Now to your question:
As far as I can see from the admin guide in the official help document (page 282; available here: SAP Cloud for Customer – SAP Help Portal Page) you will need an application key for Bing. As far as I know you have to buy that from a Microsoft partner.
Best, Christian
