Returns an array of objects whose keys are referred-user identifiers under the given referrer (user_identifier query = that referrer). Each value includes total volume and earnings for that referred user.

Omit both from_date and to_date for all-time totals. When both are set (ISO 8601, inclusive), volume and earnings are limited to that window using daily aggregates; date_joined remains all-time. Sending only one of the two returns 400.

By default (referrer_scope=active or omitted), only referred users with volume or non-zero earnings are returned. Use referrer_scope=all to also include referred users that only exist in user_referrers (no attributions yet), with zero volume and empty or zero earnings.