Alert.getCrmWindow

Hi, I am trying to get crm values from a popup dialog through AlertJS, based on the documentation , I should get the crm context, but I get the error "unable to get property 'getCrmWindow' of undefined or null reference"

  var crmWindow = parent.Alert.getCrmWindow();
  var organizationUrl = crmWindow.Xrm.Page.context.getClientUrl();
  var id = crmWindow.Xrm.Page.data.entity.getId().replace('{', '').replace('}', '');