PUT /lead/[lead_id]/funnel

{
  "funnel": funnel_id
}

curl -H 'Content-Type: application/json' \
    -H 'token: someToken' \
    -X PUT \
    -d '{"funnel": 123}}' \
    https://direct.lptracker.ru/lead/1234/funnel

{
  "status": "success",
  "result": {
    "id": 1234,
    "contact_id": 12345,
    "name": "NewLead",
    "custom": [
      {
        "id": 124,
        "name": "Владелец заявки",
        "type": "owner",
        "value": {
          "id": 12,
          "type": "staff"
        }
      },
      {
        "id": 125,
        "name": "Шаг воронки",
        "type": "funnel",
        "value": "123"
      }
    ]
  }
}