It will depend on if those channels are available in your current location. I'm in the US, and when I check the channel store I see a SmartTV channel (I don't know if that's the one you're referring to), but I fond nothing called Net IPTV. There are several channels with IPTV in their name, and a bunch with Net as part of their name.
I don't know if this link will work if you're not in the US, but this is the channel store that you can search. If it's not there, it's not available on Roku
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.
I am not a Roku employee, just another user.