getting failed to verify certificate: x509: certificate signed by unknown authority for oidc authenticator

I am running eksa on vsphere. I dont see any parameter specified in the documentation on how to provide root cert to oidc configuration. I am seeing follwing error on the api server

> oidc authenticator: initializing plugin: Get <> tls: failed to verify certificate: x509: certificate signed by unknown authority"

Start with the OIDC configuration documentation and the API server's OIDC authenticator setup to determine whether a root certificate option exists. Done means the supported way to provide the root certificate is documented or the missing configuration is specified, and the API server no longer reports the unknown-authority error.

Written by the indexing model from the issue text.