stuck on ios 13 update requested

I've had the same problem.

If you have a Mac and already use iTunes with your iOS device, then you can update via iTunes. If you don't use iTunes for your device, then you can use any Mac and Recovery Mode on the iOS device. This will make the 'Update' option available, which is not otherwise available.

https://support.apple.com/en-us/HT201263

I don't know if it works on Windows ... but you must follow the Apple support doc and enter 'Recovery Mode'. That is the only way you will have the option to 'Update'.

Attach to your computer ... press and hold the Home and Start buttons on the iPad/iPhone and keep pressing and holding until you see an image on the screen of a cable asking to be attached.

NB in iTunes you can monitor the progress of the download (once it has been initiated) from the button on the top-right of the window. A 'down arrow'. Click this to see progress.