cronopete "enable-folder-backend" does not show up in dconf Editor in 20.04

I use a combination of Timeshift and Cronopete for backups. My desktop has some internal HDDs that are used for doing backups. The system is on a separate NVMe.

I was able to get this working for Timeshift, but Cronopete expects there to be USB storage as the backup media. If you try to "Store backups in a folder", which seems is how'd I'd pick these internal HDDs as the backup destination, you get this message:

Reading the following link, it sounds like I need to install dconf Editor and toggle enable-folder-backend to on:

https://ubuntuhandbook.org/index.php/2018/07/cronopete-time-machine-like-backup-tool/

However, when I navigate there, enable-folder-backend does not appear as an option:

I'm using the "Ubuntu focal 64-bit" installer located here:

https://rastersoft.com/programas/cronopete.html

Suggestions for how to enable this?