Describe the feature

There is an extension to the OIDC flow called OpenID Connect Client-Initiated Backchannel Authentication Flow (CIBA).
CIBA introduces new authentication flow in which RPs, that can obtain a valid identifier for the user they want to authenticate, will be able to initiate an interaction flow to authenticate their users without having end-user interaction from the consumption device.

We'd love to see support for this valuable extension.

Additional context

• It introduces a new endpoint to which the authentication request is posted.
• It introduces a new asynchronous method for authentication result notification or delivery
• It introduces a new grant_type "urn:openid:params:grant-type:ciba"
• It enables a Client to initiate the authentication of an end-user through out-of-band mechanisms, supporting 3 modes (poll,ping,push)

references:

Spec: OpenID Connect Client-Initiated Backchannel Authentication Flow