Greetings hachi333,
Thanks for visiting the Apple Support Communities! It seems you're curious how to switch audio sources between your Apple devices and your Windows PC while using AirPods Pro.
Automatic switching is only supported with iOS 14, iPadOS 14, and macOS Big Sur.
While the AirPods are in your ears, test after going into the Bluetooth settings on your PC, and select "Connect" under the AirPods to reconnect. If unable to connect, then the AirPods will need to be inserted into the case.
Set up AirPods with your Mac and other Bluetooth devices - Apple Support
Kind regards.