The process is spelled out in more detail in Prof. Mollick's month-old Substack post which is linked (through a t.co redirect) from the NPR article:
There are now a lot of services that can create realistic, virtual voices. Many of these can create voices that mimic anybody with high accuracy. For my experiment, I used a service called ElevenLabs, which cost me only $5.... As you might be starting to suspect, there are a growing number of services that will create a video of you from just a script and a single photograph. I used D-ID, which costs $5.99 a month....
<https://oneusefulthing.substack.com/p/a-quick-and-sobering-g...>
I'd typically suggest that HN swap the NPR link for the disintermediated source, though NPR adds some useful observations about the political, propaganda, and fraud elements of the technology. Both probably merit first-order status at HN.
The substack article has been submitted within the past few hours here: <https://news.ycombinator.com/item?id=35274362>