Pull request #219 used MSC3266: Room summary API to display information about rooms. That MSC has not yet passed FCP and is not enabled by default on homeservers.
It should be possible to use MSC2946 instead of MSC3266 to get the same information, but in a way that is formally part of the Matrix spec, and thus more widely supported.
Pull request #219 used MSC3266: Room summary API to display information about rooms. That MSC has not yet passed FCP and is not enabled by default on homeservers.
However, MSC2946: Spaces Summary has passed FCP and is enabled by default in Synapse.
It should be possible to use MSC2946 instead of MSC3266 to get the same information, but in a way that is formally part of the Matrix spec, and thus more widely supported.