Can't use C or C++ on webOS TV?

I am trying to create a video player app using FFmpeg library on webOS TV.
So, in the LG Seller Lounge 1:1 Q&A corner
I need to use C or C++ to use the FFmpeg library.
I asked if it was possible.
Then I got the following answer.

Basically, webOS TV apps are web-based. (See Discover webOS TV and Web API and Web Engine.)
It’s not much different from general web app development.
If you can run your app on a web browser like PC Chrome, you can also run it on the webOS TV.
If you want to use FFmpeg, you can use it on your server. But TV is a client. Bring the result to the front is up to you.

The content of the answer was that you cannot use native languages such as C or C++.
is this correct?
If you have experience creating apps using native languages (C, C++) on webOS TV, please respond.

To develop native apps, webOS TV NDK is required. Without this, you can run web apps only. Just use FFmpeg on your server and create web pages for webOS TV as mentioned above. Thank you.

Please tell me how to use the webOS TV NDK.

As we said in the previous topic, webOS TV NDK is only available for contracted partners of LG. It is not open to the public.