iPad Air USB-C

The iPad (8th generation) and the new iPad Air announced by Apple at the event come with a 20W USB Type-C (USB-C) power adapter. Both models are expected to support fast charging in combination with the included cable.

iPad (8th generation) has improved charging speed in addition to processing speed

The iPad (8th generation) announced by Apple at the event on September 15, local time, has the same appearance design as the conventional model, but is equipped with an A12 Bionic processor to improve processing performance.
Apple iPad (8th generation) Features

And the included power adapter and cable have been changed to a USB-C power adapter with an output of 20W and a USB-C to Lightning cable, and it seems that high-speed charging is possible only with the included items.
Included with Apple iPad (8th generation)

The iPad series includes a USB-C power adapter with an output of 18W from the 2018 iPad Pro.
The iPhone series supports fast charging from iPhone X / 8 in 2017, but the USB-C power adapter is included only in iPhone 11 Pro / iPhone 11 Pro Max in 2019, and iPhone 11 has the same 5W adapter as before It is included.
From around June 2020, it was talked about that Apple has prepared a 20W USB-C adapter.

20W USB-C adapter included in iPad Air

The new iPad Air is equipped with a state-of-the-art A14 Bionic processor and uses the same USB-C connector as the iPad Pro for charging.
iPad Air Features

The iPad Air comes with a 20W output USB-C power adapter and a USB-C charging cable.
Included with iPad Air

Source: Apple (iPad (8th generation), iPad Air)

Source: iPhone Mania