impossible update

To update all of these requirements must be met (I’ve highlighted at least one obvious problem):

• You must be connected to a Wi-Fi network (and not a personal hotspot) unless it is an iPhone 12 series with an active 5G network connection
• The phone must be charged to at least 50%, and preferably plugged in so it stays above 50% during the update
• The phone must not be in Low Power Mode
• The phone must not be connected through VPN
• The phone cannot be in Airplane mode

Then here’s some more in-depth troubleshooting→Updating iOS: common issues and solutions - Apple Community

Go to Settings/General/Software Update, and post a screen shot of that page.

In your screen shot it was not charged above 50%. And did you have at least 6GB free?