curl --request POST \
  --url https://api.example.com/variables \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "variable": {
    "type": "ENV",
    "value": "<string>",
    "name": "<string>"
  }
}
'

{
  "variable": {
    "id": "kSuB9Gf6aD4",
    "createdAt": "2023-11-07T05:31:56Z",
    "updatedAt": "2023-11-07T05:31:56Z",
    "type": "ENV",
    "value": "<string>",
    "name": "<string>"
  }
}