Missing index.yaml in Helm repo

[PeterCahnCSI]

Hi there,
I am trying to include the "wiki" Helm chart as a dependency of another Helm chart we are using in our workflow:

dependencies:
- name: wiki
  version: 2.2.23
  repository: https://charts.js.wiki/charts

As I run helm install command I get something like this (same happens when trying helm repo update or helm dependency build

.\scripts\helm-install-svil.ps1
Getting updates for unmanaged Helm repositories...
...Successfully got an update from the "[http://repo.ecosis.csi.it/artifactory/helm-base"](http://repo.ecosis.csi.it/artifactory/helm-base%22) chart repository
...Successfully got an update from the "[http://repo.ecosis.csi.it/artifactory/helm-base"](http://repo.ecosis.csi.it/artifactory/helm-base%22) chart repository
...Successfully got an update from the "[http://repo.ecosis.csi.it/artifactory/helm-base"](http://repo.ecosis.csi.it/artifactory/helm-base%22) chart repository
...Unable to get an update from the "[https://charts.js.wiki/charts"](https://charts.js.wiki/charts%22) chart repository:
        failed to fetch https://charts.js.wiki/charts/index.yaml : 500 Internal Server Error
Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "bitnami" chart repository
Update Complete. ⎈Happy Helming!⎈
Error: no cached repository for helm-manager-e14376f1ac526bdf092adf495bc1203449c70ba64f759c998b960c99dea49ce3 found. (try 'helm repo update'): 

Is it possible to have this file created in your repo so to make this work? Or if there is any workaround for this, please let me know.

Thanks in advance.