Connecting wheel controls to aftermarket Android head unit

[e87guy]

I have a 2011 118D E87 N47. The previous owner has installed an aftermarket Android head unit into the storage box on top of the dashboard. The head unit is a MEKEDE head unit from AliExpress. Here are the specs:

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The center console armrest buttons work with the head unit, but the wheel controls don't. The wheel controls don't even work when I use the stock Business CD radio.

To get the music/sound from the head unit, I need to set the stock radio to "AUX".

The head unit also has a reverse camera, Bluetooth, and a microphone, which all work.

So how do I connect the wheel controls to the head unit? How do I know what type of cable to get, if that's what I should do? What other info can I provide here?

Any pointers and help is appreciated!