curl --request POST \
  --url https://letterby.com/api/v4/actions \
  --header 'Content-Type: application/json' \
  --header 'apiKey: <api-key>' \
  --data '
{
  "name": "<string>",
  "contactId": "<string>",
  "increase": 1
}
'

{
  "data": {
    "action": {
      "id": "<string>",
      "name": "<string>",
      "increase": 123,
      "createdAt": "2023-11-07T05:31:56Z",
      "updatedAt": "2023-11-07T05:31:56Z",
      "subId": "<string>"
    }
  }
}