technically… yes. it does “support” IAP features available within the Android OS via the Capacitor CLI build framework’s support for Android OS related features.
that said, this tool only provides a easy-to-use “single-click-esque” automation of the build tasks and doesn’t actually have any involvement with or control over the actual in-game/in-app features of the game/app since it just gives a GUI (Graphical User Interface) to a process that would normally be done via Command Line.
if you want to use IAP features in your RPG Maker games, you’ll need to handle that with a plugin specific to the game engine you’re using.