InsightIQ 5 REST API, list quotas?

Hi,

I'm trying to get a list of all the quotas on a PowerScale cluster via the REST API in InsightIQ 5.

I've played around with CURL and I see that there is a "quota_usage" key in the "data-element-types" in the reporting API part.

But I cannot figure out how to actually make use of it.

I've got my cluster guid from https://<insightiq>:8000/insightiq/rest/clustermanager/v1/clusters

I've tried querying https://<insightiq>:8000/insightiq/rest/reporting/v1/timeseries/download_data?cluster=90e2baf093a49e4fa25a4f1e98b8f659d06c&key=quota_usage

But all I get then is "Internal Server Error".