get
https://{APP_DOMAIN}/api/3.2/subscriptions/statistics
Returns daily time-series data for a given metric across subscriptions matching the current filters. Supports metrics: sends, opens, clicks, complaints, list_unsubscribes, unsubscribes, new, duplicate, reactivate, renew, invalids, subscribers, conversions, clicks_funnel, revenue, epc, rpm, open_rate, click_rate, conversion_rate.