Bearer authentication header of the form Bearer <token>, where <token> is your auth token.
Pass the optional Idempotency-Key header to make the request safe to retry. The key can be up to 256 characters. The server stores the canonical request body and behaves as follows:
Entries expire after 24 hours. Use a unique key per logical send (for example, an order or signup ID).
1 - 256Optional when templateId is provided
1ID of a template from the dashboard
11Custom headers to included with the emails
10Retrieve the user