JupyterHub z2jh CORS issue


Trying to get working JupyterHub Lab notebook in Z2JH (v1.1.1).
Getting CORS error while trying to load Lab extensions:

JupyterHub is running in AWS EKS cluster within VPC.
To connect to JupyterHub we use LoadBalancer, which is being created while deploying JupyterHub helm chart, applying AWS annotations (nlb, timeout, cert). Then creating rule in Route53.

Assuming, that I need to add headers or some JupyterHub setting allowing CORS, but not sure exactly where to do this.