Disclaimer: Bluetooth MIDI is not officially supported. A third party source might be able to connect the iPad app to Bluetooth MIDI keyboards. Please refer to this article. A wired MIDI connection is still strongly recommended for the best experience.
Through our testing, Bluetooth MIDI connectivity with the Playground Sessions computer app has proven to be unreliable. For this reason, we do not recommend connecting your keyboard to the Playground Sessions computer app using Bluetooth MIDI.