How do I call game plugin functions in custom Character class?

Thanks for the suggestions Bob, I have followed your tutorial and created the required files for my plugin, but now I am getting this error when I build the game

LogPluginManager:Error: 'Descriptor file ‘…/…/…/…/…/…/Users/admin/Documents/Unreal Projects/PluginProject/Plugins/TestPlugin/TestPlugin.uplugin’ could not be loaded. Failed to read file. {1}

have you seen this error before? if you can give me some tips on where I should start looking that would be awesome