curl --request POST \
  --url https://api.meetcampfire.com/ca/api/user_currency \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "currency": "USD"
}
'

{
  "id": 123,
  "name": "<string>",
  "last_modified_at": "2023-11-07T05:31:56Z",
  "is_deleted": false,
  "deleted_at": "2023-11-07T05:31:56Z",
  "created_at": "2023-11-07T05:31:56Z",
  "customer": 123,
  "currency": "USD"
}