@spec get_usage(Tesla.Env.client(), String.t(), keyword()) ::
  {:ok, PropOddsAPI.Model.Usage.t()}
  | {:ok, PropOddsAPI.Model.HttpValidationError.t()}
  | {:error, Tesla.Env.t()}

Retrieves the API usage statistics for the provided API key.

Parameters

• connection: The Tesla.Env.client() used to make the HTTP request.
• api_key: The API key used for authorization, as a String.t().
• opts: Optional parameters provided as a keyword list (currently unused).

Returns

• {:ok, PropOddsAPI.Model.Usage.t()}: On success, returns the API usage statistics.
• {:ok, PropOddsAPI.Model.HttpValidationError.t()}: If there's a validation error with the HTTP request.
• {:error, Tesla.Env.t()}: On failure, returns the error within the Tesla environment.