The RP must have obtained the key out-of-band during the registration
process
The Response Type request parameter 'response_type' determines
which tokens are returned from the endpoints used.
Informs the OpenID Provider of the mechanism to be used for returning parameters
from the Authorization Endpoint. The default and only option for the Authorization Code flow is 'query'.
We don't support the 'query' response_mode for the Implicit flow.