Hello, I’m Nathan, and I’ll be assisting you today. My livelihood depends on your positive feedback, so your satisfaction is my highest priority.
Hi there, sorry to hear you're having trouble,
the short answer is that you can't, at least not directly through the tv. These smart tv's are limited to the "apps" which are developed and provided by Samsung, which are very limited. The tv uses a unique operating system/browser, also a limited samsung product, that mean's that you can't just go to an "app store" like you would on an iphone or android device and install anything you wish. The tv is only capable of working with the purpose made apps provided by the tv maker.
So in short, you can't do it, at least not with the apps currently made available by samsung, through the built in smart tv function.
There are however some other options, such as using an external "smart" device like a Roku or Chromecast (streaming the tv3 player, rte player channel, etc) that can connect to the tv, which have far more "apps" available than what the built in smart service on the tv offers.
Another option would be to connect your computer to the tv, essentially using the tv as a large monitor. That would be done with vga/hdmi cables (depending on your tv model)
If you'd like more info on any of these options, how to hook them up, etc, I'll be happy to advise further.
You can also potentially wait for a future update from samsung that would possibly offer this added content. You might even try contacting samsung to request they add these channels/features. It is not a guarantee, but it won't hurt to try either.