[Question] Azure Application Gateway for Containers mTLS header forwarding possible?

We are migrating to Azure Kubernetes Service with Azure Application Gateway for Containers and we have the following use case:

Some of our clients use mTLS when calling our APIs, while others do not.

What we want to achieve is to have TLS termination at the Gateway level, and after that the certificate thumbprint/fingerprint to be passed downstream to the backend target(s) as a Request Header (because this is needed for a logic that the service has).

Is that achievable?

Based on the documentation specific here - I can't find anything that explains that so I would like to see if someone has any recommendations on if and how can this be achieved.

https://gateway-api.sigs.k8s.io/guides/user-guides/tls/

https://learn.microsoft.com/en-us/azure/application-gateway/for-containers/how-to-frontend-mtls-gateway-api?tabs=alb-managed

Thanks a lot in advance