externalRef:
Fundor’s lead reports and its call-center records show the source of each lead: submitted by your API, or through one of your athletes’ links.
First channel wins
If a person already had a Fundor account before you linked it (see Account linking), the account stays attributed to wherever it came from first. Fundor still records that you linked it, and the account is usable by you from then on.externalRef
Use a stable ID from your own system, unique per record type. It lets you match Fundor records to yours and makes retries safe: the same externalRef never creates a second record.