Post employee pension

curl --request POST \
  --url https://api.sandbox.flowpayroll.ai/v1/pension/employee-pension \
  --header 'Content-Type: application/json' \
  --data '
{
  "employeeId": "<string>",
  "pensionGroupId": "<string>",
  "enrolmentDate": "2023-12-25",
  "sendLetters": true
}
'

{
  "message": {
    "text": "<string>",
    "token": "<string>",
    "tokenArguments": [
      {
        "name": "<string>",
        "value": "<string>"
      }
    ]
  },
  "content": {
    "data": {
      "organisationId": "<string>",
      "employeeId": "<string>",
      "pensionGroupId": "<string>",
      "enrolmentDate": "2023-12-25",
      "createdBy": "<string>",
      "createdDate": "2023-11-07T05:31:56Z",
      "updatedBy": "<string>",
      "updatedDate": "2023-11-07T05:31:56Z"
    },
    "metadata": {
      "dateFormat": "<string>",
      "dateTimeFormat": "<string>"
    }
  }
}