AppleTV is not showing up as an available channel on my Insignia Roku TV model 5302X

That model number appears to be missing from this list so my first guess would be that it’s not supported.  I’m having trouble finding much information about that TV. 

Another reason that people can see a version for professionals but not the “main” app is because they are outside of a supported country.  Where are you located?

rhythmdbCurious if you've ever subscribed and are aware they raised the fee to $9.99 from $6.99. I subscribed when it first began and loved it but cancelled  many months ago due to lower quality and lack of new content. And like others have said, its only available in select counties, of which the U.S. is one of them. Regardless, you're really not missing much in my opinion

rhythmdb, I'm going to agree with Strega2 and say it's not supported on that TV.  I only see Roku TV "5000X" listed in their hardware reference , so assuming that covers your TV, it's a bit of an oddball with a weird processor and no accelerated graphics which I'd bet is required.

You can always connect a new Roku device to your Roku TV if you really, really have to have that app.