JenkinsX in Kubernetes

I'm installing JenkinsX on top of Kubernetes Cluster (on-premise). Passed all parameters to the jx install command.I'm passage the corporate GitHub credentials and using Helm2 with no tiller. Getting the error - FATAL : helm init failed: after 3 attempts, last error:failed to run 'helm repo add Jenkins-x https://storage.googleapis.com/chartmuseum.jenkins-x.io' is not a valid chart repository or cannot be reached: Get https://storage.googleapis.com/chartmuseum.jenkins-x.io/index.yaml: x509:certificate signed by unknown authority'. Appreciate if anyone can shed any light on this issue. I don't have control to disable the corporate proxy. Is there a way to disable the proxy or certificate.

Thanks in advance