For the notification, you can enhance the echo command with #shownotification. This displays a notification window. Below a screenshot on how this looks on Windows (works the same on Mac/Linux, just the dialog looks a bit different. It is generated by the browser itself).
echo | hello! | #shownotification
Now, if you want to get such a dialog only in specific situations (like on error), you can work with if/then or OnError | #goto | Label => Jumps to “LABEL” if an error happens. You find an example in the DemoIfElse macro. And below this label would then be the echo command that shows the notification.
