Create sales agents in bulk

{
  "new_agents": [
    {
      "email": "alice@example.com",
      "external_agent_id": "abc123",
      "name": "abc123",
      "phone": "abc123",
      "seller_id": "739b63c2-9e58-4964-b38d-4ebb424de242",
      "seller_store_id": "abc123"
    }
  ]
}

{
  "count_new_agents": 1,
  "failed_agents": [
    "abc123"
  ]
}