Query for Memory usage in singlestat panel (in grafana)

Please provide query for MEMORY USAGE aggregation of multiple servers in singlestat panel.

Im using below query but not working in singlestat panel (it is giving data on Prometheus)
((node_memory_MemTotal{job=“api-server”} - node_memory_MemFree{job=“api-server”} - node_memory_Cached{job=“api-server”}) / (node_memory_MemTotal{job=“api-server”} )) * 100

Could you please provideproper query for multple servers memor usage aggregation in grafana.

don’t know prometheus query language that well, might be better to ask in prometheus forum.

Or maybe someone who knows prometheus really well will see this and answer you .)