the biggest problem with this is that only covers the video hosting - for witch you do need a solid hosting - recommended with CDN.
to use that video on a channel you need to ad the video link into a json feed or into the SDK settings.
just because you upload a video into a wp installation you will not have a channel setup , way more to it than just video upload.
so @nikola123 Like @RokuDavid recommended look into the developer documents , it would help to understand what and how ... you will realize quite fast that using wp is not a solution in any way for a proper and quality Roku channel.
Building a TV Channel can be easy … if you have a right tools ===>> https://tv-channel.info/