How do I move the backup to my new phone?

When you first set the new phone up, you were offered the option to restore data from an iCloud backup or a backup on a Mac or PC over to your new phone.

It sounds like you passed on that opportunity, so if you still want to restore from a backup, you will have to erase the new phone and start over again from the "hello" set up screen.

When the option to restore from an iCloud backup or backup on a computer appears on the screen, make sure to select the option you want to use. Details below:

Use iCloud to transfer data from your previous iOS or iPadOS device to your new iPhone, iPad, or iPod touch - Apple Support