Create a new dynamic rule

Example request

{
  "forecastExternalVariableId": "EXTERNAL_VAR",
  "amount": 100,
  "startTime": "12:00",
  "endTime": "13:00",
  "shiftTypes": [
    {
      "externalShiftTypeId": "EXTERNAL_SHIFT_ID",
      "amount": 10
    }
  ]
}