Installing backup of old iPad onto new iPad from PC

I just bought a new iPad 10th gen, but the data transfer from my old iPad (traded in) was incomplete. I made a backup of the old iPad onto my PC (NOT the iCloud). Every resource I've consulted has told me that iTunes will allow me to install that backup. But it doesn't. The Restore Backup button is grayed out. I've located the backup file on my PC. It's in the Apple/MobileSync/Backup folder, where I understand it is supposed to be, but clearly iTunes isn't seeing it. Does anyone know how I can remedy this problem and install this backup onto my new iPad?

Thanks.