How to add Federation/Thanos to standard Prometheus

Hi all.

I installed Prometheus/rancher-monitoring into a new test cluster on my Rancher 2.5.7 via the “Apps and Marketplace”. I would like to expand this out to Prometheus Federation so that I can collect data from other Prometheus sources. Is it possible to do this, and if so, how? Is Thanos a requirement?

Happy to answer questions about my environment.
– Birl