Braves on Palmetto Sports Network

I searched and could not find it either.  It looks like it is a relatively new Sports network channel so it is possible they have not developed an app for Roku.  It is up to that network to create an app for Roku as Roku has no control over who develops an app that works on the devices.  I suggest contacting Palmetto Sports Network customer service and asking them to create an app for Roku.  Since they are new, they might be in the process of developing one.  Keep in mind that a lot of broadcasters either choose not to make a streaming app for their channel or choose to stream as part of a service with a provider and are therefore not accessible without a subscription to some type of provider-based channel package, similar to a cable package.