{ "summary": "Add subscriber to sequence by email address", "method": "POST", "path": "/v4/sequences/{sequence_id}/subscribers", "tag": "Sequences", "request_body": { "email_address": "string" }, "response": { "subscriber": { "id": 1, "first_name": "string", "email_address": "string", "state": "active", "created_at": "string" } } }