How do I access my TS-233 over the internet?
Via MyQNAPcloud link.
Do you want a secure and safe solution or one that is open to hackers?
Start with some basics. What specifically are you trying to “access over the internet”? (web server, files, music, video, etc)
Do you have a router capable of running a free VPN Server? That is generally the best, safest, reliable and most secure way. It also depends on your ISP and what type of access you have, if you have DDNS.
Never forget to have a proper backup strategy, particularly if you are exposing anything to the internet.