USB Splitters?

Thank you for this clarification. What you are attempting to achieve is at best inadvisable - and at worst, may cause significant damage to your expensive Apple devices. USB is essentially a one-to-one connection - i.e., one charging port to one device.

If you intend to simultaneously charge multiple devices from a single Power Adapter, the Power Adapter must have multiple connections; one port = one device!

Here is an example of a Power Adapter that is designed to simultaneously safely charge multiple devices…:

• mophie speedport 120 4-port GaN wall charger (120W)

https://store.apple.com/uk/xc/product/HPZE2B/A

Also consider that your sixth generation iPad Pro supports USB PD (Power Delivery) over USB-C. When charged from a compatible Power Adapter, you iPad will optimally charge at its maximum supported charging rate of 20W; USB-C Power Delivery can operate at higher voltages than standard USB 5V.

When your iPad Pro is instead connected to a USB Type-A power source, the maximum charging rate is limited to 2.4A @5V. Be aware that many computer/accessory USB ports cannot source sufficient power to charge an iPad. Unless explicitly designed for charging connected devices, computer USB ports are typically limited to 0.5-1A @5V (i.e., 2.5-5.0W).

In summary, I urge you to abandon your current intent. You are having difficulty finding a “splitter” because you are attempting something that you shouldn’t.

Setting aside the hub for a moment - what, precisely, are you attempting to achieve or connect with your iPad?

USB is an often misunderstood interface. You cannot, by example, interconnect two USB Type-A connections (as these are USB Controllers) - but must instead connect USB Type-A to a Type-B connection.

Unlike USB Type-A, USB-C is bidirectional. You can interconnect two USB-C devices; if compatible, they will auto-negotiate which device will assume the role of the USB Controller.