dask-gateway: Problems with getting API-dask-Gateway Pod to start

I’m trying to create a dask cluster on existing Kubernetes using dask gateway I used the default values.yaml as a baseline and added the following code to extraConfig:

extraConfig: |
from dask_gateway_server.options import Options, Integer, Float, String

       def option_handler(options):
           return {
              "worker_cores": options.worker_cores,
              "worker_memory": "%fG" % options.worker_memory,
              "image": options.image,
       }

        c.Backend.cluster_options = Options(
            Integer("worker_cores", 2, min=1, max=4, label="Worker Cores"),
            Float("worker_memory", 4, min=1, max=8, label="Worker Memory (GiB)"),
            String("image", default="daskgateway/dask-gateway:latest", label="Image"),
            handler=option_handler,
       )

I performed helm installation based on this updated values.yaml file and everything runs except the API-Dask-Gateway pod. Without this extraConfig it runs fine, but I don’t get options for clusters. Please help. Thanks, Vinh