Troubleshooting Prometheus to Grafana data fetching issues when monitoring a MongoDB cluster in Kubernetes.

I am currently trying to monitor a MongoDB cluster in Kubernetes using Prometheus and Grafana, but I am having trouble getting data from Prometheus into Grafana. I have configured Prometheus to use the MongoDB exporter and can see the targets in Prometheus, but I am unable to fetch data in Grafana.
Can you please provide some guidance on how to resolve this issue? Any help would be greatly appreciated.