Step 1 of 2 for submitting a lead. Send the answers you are about to submit in lead_submission. The response contains a token, json.encrypted_data, that is valid only for exactly those answers. Then call POST /api/v3/partners/{partner_id}/lead_forms/create with the same lead_submission, unchanged (same keys, order and values), and the token in authenticity_tok. The token does not expire and is not tied to a listing. The HTTP status is 201; the status field in the body is always 200.