You can see various statistics on the Strix Cloud’s Web Console, but there is no API to get the statistics information from clients. However, some tricks allow it to some extent.
To know the number of rooms, you can search for rooms with no conditions and count the found rooms. Summing up the number of players in each room (memberCount property) during the process also gives you the effective number of connections. However, if there are many rooms, rooms may be created or deleted, or players may join or leave rooms during the process, so the resulting numbers should be considered estimates.