helm example for running matomo in subpath

I'm trying to get matomo run in Kubernetes in subpath via Ingress, like:
https://example.com/matomo

However, it seems complicated, and I did not get it working.
I've followed these instructions: https://matomo.org/faq/how-to-install/faq_98/
but it's not clear to me, where this config should be made: in ingress or in nginx proxy container (part of the helm example) or both.

Could you provide an example config on how this is configured properly?

Start with the linked Matomo subpath instructions and the existing Helm example, then trace how Kubernetes Ingress and the nginx proxy container are configured. Document a working example showing whether the subpath settings belong in Ingress, the proxy, or both, with Matomo available at /matomo.

Written by the indexing model from the issue text.