Rancher Monitoring v2.4 - Prometheus external applications

Hi All,

So in Rancher we can install Grafana and Prometheus to monitor the cluster which is great.
Can I use Prometheus to get stats from Applications outside of the K8s cluster ?

I don’t want to install/maintain a separate instance of Prometheus/Grafana and waist resources.
I can expose these UIs via an ingress

Is there a way to add the scrape_configs via UI in Prometheus? If not how do I change the config yaml file to add an external service to monitor?
Will a helm upgrade of the Cluster Monitoring break my changes?
How does the access/permissions work If I do this ?
Sorry for all the questions.

Thanks for any help