Generate client proposal

curl --request POST \
  --url https://api.tilt.io/custom/org/{organization_uuid}/client/{external_id}/proposal/ \
  --header 'Content-Type: application/json' \
  --header 'X-Api-Key: <api-key>' \
  --data '{
  "optimized_weights": [
    {
      "ticker": "<string>",
      "weight": "<string>"
    }
  ]
}'

{
  "orders": [
    {
      "ticker": "<string>",
      "amount": "<string>",
      "type": "Market",
      "tax_lot": [
        {
          "rank": 123,
          "cost_basis": "<string>",
          "quantity": "<string>",
          "trade_date": "2023-12-25",
          "gain": "<string>"
        }
      ]
    }
  ]
}