Error when importing as a Prometheus source in Grafana

[Amxx]

I started the Docker container, and binded the ports

It seems to work, and querying curl http://gethexplorer:9090/metrics does return the expected data.
However, when I try to add this as a datasource in grafana, I get the following error:

Error reading Prometheus: client_error: client error: 404

Not that if I target another host/port, I get a different error (dial tcp 172.18.0.7:9091: connect: connection refused). My understanding is that Grafana is expecting the /api/v1/query to be available, but that is not the case.

Is this docker image using an old version of prometheus that grafana doesn't support ? Is there another way to configure grafana ?