Apache on Mac Sierra 10.12.5

[Manal Helal <manalorama@xxxxxxxxx>]

I followed this guide to install apache on Sierra 10.12.5:

https://medium.com/@JohnFoderaro/how-to-set-up-apache-in-macos-sierra-10-12-bca5a5dfffba

And it worked locally for a while logged in using the same Mac user.

The only problem is I need this for dynamic dns and to have external global access. I followed the steps on the 172 rated first reply in this post:

https://stackoverflow.com/questions/2001881/correct-owner-group-permissions-for-apache-2-site-files-folders-under-mac-os-x

Now both the domain name access and localhost access gives this error:

Forbidden

You don't have permission to access / on this server.

Please advise how to resolve, 

Thank you very much, 

Manal