Charging specifications of iPad Smart Connector

I'd like to attach my iPad to a wall (or a monitor arm) with a magnetic case, and the idea is to charge it using the three pins on the back (called Smart Connector). I know this has to work somehow, because the Smart Keyboard from Apple does it, but they are too expensive just to cut up (except maybe getting a broken one from somewhere, no luck there so far), and there are no other products that charge with this port as far as I know. What are my options here? Can I just wire two of the pins to a 9V 2.22A or 5V 3A DC source, like it would be possible with the USB-C port? Which pins do I need to take? Are there any available spare parts that would simplify the process? Thank you for answering if you know more!