External Keyboard Input and Shortcuts
If your external keyboard does not work while using Studio, there may be an iPad setting enabled that is interfering.
Full Keyboard Access is an Apple feature on the iPad that allows you to use shortcuts to navigate the iPad, instead of using the touchscreen. Having this enabled can interfere with keyboard input and using Astropad Studio shortcuts.
How to turn off Full Keyboard Access
On the iPad, go to Settings > Accessibility > Keyboards > Toggle Full Keyboard Access off