How to pull a helm chart from a private repository using the project or group name in the URL?

I have created a private project, let’s call it mygroup/secret_chart. This project contains a Helm chart, and one of its CI jobs pushes this chart to the project’s package repository using curl (as outlined in the documentation. When i check the Package Registry of this project, i can even see my secret-chart’s brand new 0.3.0 version.

Back to the documentation, i did

helm repo add --username myusername --password FancyAccessToken secret-project https://gitlab.com/api/v4/projects/mygroup%2Fsecret_chart/packages/helm/stable
helm repo update

So far so good. However, when i do helm pull secret-project/secret-chart, i get this error:

Error: failed to fetch https://gitlab.com/api/v4/projects/mygroup/secret_chart/packages/helm/stable/charts/secret-chart-0.3.0.tgz : 404 Not Found

In the background something, probably Helm, changed the %2F in the repo URL to a plain /. If i change the repo URL to use the numeric project ID, it works as expected (and actually, that’s exactly what the documentation mentioned above does, too).

Question is, am i constrained to use the project ID here, or do you guys know of a way to use the project name? What would be even better, is if i could use the group name in the repo URL, like i can with PyPI.

I was only ever able to get it working with the project id.