How to supply options to helm upgrade in webUI

I am trying to install democratic-csi. The tutorial says first define repo then use:

helm upgrade \
--install \
--create-namespace \
--values freenas-nfs.yaml \
--namespace democratic-csi \
--set node.kubeletHostPath="/var/snap/microk8s/common/var/lib/kubelet"  \
zfs-nfs democratic-csi/democratic-csi

I have added the helm chart to App. But when rendering, the webUI does not allow me to specify options like --values. It only contains some toggles as shown in here

I thought may I should define values.yaml to make a new local git. but I am not sure if it is the way to go, especially values.yaml is already defined in the original chart repo.