Get Billing Usage

{
  "cycle": "string",
  "status": "none",
  "activeKeywords": 0,
  "keywordMax": 0,
  "relevantMentions": 0,
  "includedMentions": 0,
  "overageMentions": 0,
  "billableMentions": 0,
  "billedMentions": 0,
  "trial": {
    "endsAt": 0,
    "mentionsUsed": 0,
    "mentionsLimit": 0,
    "expired": true
  }
}

{
  "error": {
    "code": "string",
    "message": "string"
  }
}