Windows 10 desktop Trust This Computer?

I need to connect to iTunes to backup iPhone contents and sync my iPhone XR with new purchases from the Store.

I get the message "Trust This Computer? Your settings and data will be accessible from this computer when connected wirelessly or using a cable."

My specifications are:

• iTunes Version 12.10.7.3.
• iPhone XR iOS version 13.3.1. Version 13.5 available.
• Windows 10 Version 1903 for x64-based Systems (KB4497165).

I have tried previous suggestions:

• Reset Location & Privacy.
• Tried a different USB cable.
• Turned off Wi-Fi.
• No personal hotspots defined.
• Found this article: https://support.apple.com/en-us/HT202778. Followed the suggested steps with no luck.
• Found this article: https://support.apple.com/en-us/HT204095. Look at step four. "If you see a Trust this Computer alert, unlock your device and tap Trust:. How do I unlock the device? Which device -- PV or iPhone?

Any suggestions?

When connected, the phone and computer need to trust each other for data to be exchanged. As a general rule of thumb the computer will trust most usb devices. However, because phones charge through the usb to lightning cable it may be unwise to trust every host device to which the phone is connected.

Because of this you need to unlock your phone (just get past the lock/pin/password/faceID screen) and give permission to "trust this computer", which will usually just pop up on the screen.

If this is still not working, restarting the phone and computer before trying again may be a good place to start.