Registering non-AWS private docker repos with SageMaker Model Registry

SageMaker announced months ago "Amazon SageMaker Model Registry announces support for private model repositories" (https://aws.amazon.com/about-aws/whats-new/2023/10/amazon-sagemaker-model-registry-private-model-repositories/). But I cannot find any document telling how we can do this. I opened the Model Registry in Studio but didn't find a way to register non-AWS docker repos there. How can we do this?