Since you mentioning Kitsu and Shotgun I assume you mean ProjectManager type plugins instead of RenderManagers.
In the Prism_PluginName_Functions.py file there is an "isActive" function. The plugin shows up in the plugin list only if this function returns True. ProjectManager plugins by default return True only when run in Python 2, but Prism is using Python 3 in the latest version.
This is a remaining behavior from a while ago, when the Shotgun Python API was only compatible with Python 2. I'll change the default for this function to return always True in the next update.
Since you mentioning Kitsu and Shotgun I assume you mean ProjectManager type plugins instead of RenderManagers.
In the Prism_PluginName_Functions.py file there is an "isActive" function. The plugin shows up in the plugin list only if this function returns True. ProjectManager plugins by default return True only when run in Python 2, but Prism is using Python 3 in the latest version.
This is a remaining behavior from a while ago, when the Shotgun Python API was only compatible with Python 2. I'll change the default for this function to return always True in the next update.