code: func CheckPushConf() error {
  	if !PushConf.Ios.Enabled && !PushConf.Android.Enabled {
  		return errors.New("Please enable iOS or Android config in yml config")
  	}
  
  	if PushConf.Ios.Enabled {
  		if PushConf.Ios.KeyPath == "" && PushConf.Ios.KeyBase64 == "" {
  			return errors.New("Missing iOS certificate key")
  		}
  
  		// check certificate file exist
  		if PushConf.Ios.KeyPath != "" {
  			if _, err := os.Stat(PushConf.Ios.KeyPath); os.IsNotExist(err) {
  				return errors.New("certificate file does not exist")
  			}
  		}
  	}
  
  	if PushConf.Android.Enabled {
  		if PushConf.Android.APIKey == "" {
  			return errors.New("Missing Android API Key")
  		}
  	}
  
  	return nil
  }
docs: // CheckPushConf provide check your yml config.