Prometheus missing in Raspberry Pi installation?

I installed Grafana on a Raspberry Pi and have problems to get Prometheus running.
My Grafana is on v9.4.3, and I installed it by following this tutorial: Install Grafana on Raspberry Pi | Grafana Labs
But if I create Data source Prometheus it does show me a red label Error reading Prometheus: Post "http://localhost:9090/api/v1/query": dial tcp [::1]:9090: connect: connection refused
My Grafana Logs show this:
$sudo tail -n 5 /var/log/grafana/grafana.log

logger=cleanup t=2023-11-08T06:44:17.004018974+01:00 level=info msg="Completed cleanup jobs" duration=38.597105ms
logger=cleanup t=2023-11-08T06:54:17.001566819+01:00 level=info msg="Completed cleanup jobs" duration=36.647938ms
logger=data-proxy-log userId=2 orgId=1 uname=novski path=/api/datasources/proxy/uid/Qk-__714z/api/v1/status/buildinfo remote_addr= referer=http://ug-tech-grafana:3000/datasources/edit/Qk-__714z t=2023-11-08T06:56:07.58732581+01:00 level=error msg="Proxy request failed" err="dial tcp [::1]:9090: connect: connection refused"
logger=context userId=2 orgId=1 uname=novski t=2023-11-08T06:56:07.587591471+01:00 level=error msg="Request Completed" method=GET path=/api/datasources/proxy/uid/Qk-__714z/api/v1/status/buildinfo status=502 remote_addr= time_ms=24 duration=24.366429ms size=0 referer=http://ug-tech-grafana:3000/datasources/edit/Qk-__714z handler=/api/datasources/proxy/uid/:uid/*
logger=context userId=2 orgId=1 uname=novski t=2023-11-08T06:56:07.620386285+01:00 level=info msg="Request Completed" method=POST path=/api/ds/query status=400 remote_addr= time_ms=24 duration=24.529333ms size=140 referer=http://ug-tech-grafana:3000/datasources/edit/Qk-__714z handler=/api/ds/query

How can I verify if Prometheus is installed correctly?
Am I overlooking something I had to do previously?

If Prometheus has to be installed separately, why is that not mentioned in the Raspberry Pi Installation section?

Hi @novski

I have not followed the tutorial that you linked to, but I believe whenever one installs Grafana OSS it does not include Prometheus, and when one installs Grafana Cloud, it does contain an instance of Prometheus that you can send metrics to & use with Grafana Cloud.

Grafana and Prometheus are two different products. They can be used together or separately. What is your goal here?