You cannot add channels or watch LiveTV to Plex Cloud. You need to have a local server and for LiveTV a tuner to get your TV.
Do you know how Plex works and did you read about it before you bought a Plex Pass? https://support.plex.tv/hc/en-us/articles/200288286-What-is-Plex-
I do not think you can add “channels” to “Plex Cloud.”
For regular access to media you own you need to get the media in a usable format and correctly named and the upload it to one of the supported cloud systems.
You have to have a local server to use LiveTV.
Do you also understand that you have to have a TV tuner as listed here (https://support.plex.tv/hc/en-us/articles/225877427-Supported-DVR-Tuners-and-Antennas) to use the LiveTV option?
Also, not sure how you are using Kodi but LiveTV is only available on certain Plex clients.
it would be really helpful if you read the FAQ articles on this stuff instead of just asking for people to do your research for you.