Create personal voice
I was able to figure out why the download option for personal voice creation was just defaulting. Firstly, you need to make sure you are on iOS 17 and not on the iOS 18 beta. Secondly, if you have any devices connected to the Apple account the device you’re creating the personal voice on you may try setting up the beginning of the personal voice on that device then moving to the device you plan to use.
iPhone 15 Plus