DevonThink to Go mobile Inbox location?

I have a portable scanner that connects wirelessly. It can deliver scans directly to Dropbox. I have Devonthink configured to work seamlessly between my iPhone and my Mac using Dropbox. I was wondering on the mobile version configured to use Dropbox stores, is there a physical location that would be the “Inbox” folder like the Mac has to drop files in and Have Devonthink get them automatically?

No, this is not possible. macOS ≠ iOS so the filesystem is different and treated differently in iOS.
You also cannot index files in DTTG2, so you can’t point it at your Dropbox to add these files automatically.