How configure graph "Add all your Checkmk servers as monitored hosts to Checkmk to render this graph. Specifically, we are missing the 'Site [SITE] "

Ah ok, sorry, now I realise you got the demo.
From my part, don’t know how to solve this.

However, I believe it would be in tribe29’s interest to enable people to upgrade their agents on monitoring hosts via any method on a demo version. With docs specifying the steps.

Best wishes to the technical writers, they for sure have a lot to write for this 2.0 release.