The USB-C Multimedia M1 Adapter has two USB-C ports with different jobs:

• USB-C PD port: pass-through charging for the host device the adapter is plugged into, up to 85W with a 100W power adapter and a proper e-marked cable. The USB-C PD port does not support data transfer or video.
• USB-C data port: connects a USB-C device or peripheral at up to 5Gbps. The USB-C data port does not support charging or video.

If the adapter is plugged into your iPad, the USB-C PD port charges the iPad but does not transfer data. Neither USB-C port charges an iPad connected to the adapter as a peripheral.