code: func (api *API) UpdateSpectrumApplication(zoneID, appID string, appDetails SpectrumApplication) (SpectrumApplication, error) {
  	uri := fmt.Sprintf(
  		"/zones/%s/spectrum/apps/%s",
  		zoneID,
  		appID,
  	)
  
  	res, err := api.makeRequest("PUT", uri, appDetails)
  	if err != nil {
  		return SpectrumApplication{}, errors.Wrap(err, errMakeRequestError)
  	}
  
  	var spectrumApplication SpectrumApplicationDetailResponse
  	err = json.Unmarshal(res, &spectrumApplication)
  	if err != nil {
  		return SpectrumApplication{}, errors.Wrap(err, errUnmarshalError)
  	}
  
  	return spectrumApplication.Result, nil
  }
docs: // UpdateSpectrumApplication updates an existing Spectrum application.
  //
  // API reference: https://developers.cloudflare.com/spectrum/api-reference/#update-a-spectrum-application