Error creating textual authentication agent: Error opening current controlling terminal for the process (`/dev/tty')

I installed the Boot2Qt 6.5.7 Raspberry Pi image from the installer and got this while trying to flash an SD card. I'm not surprised that it's a pain: it requires sudo access.

When it fails, it would be best if the wizard would just give me the path to the image so I can dd it. Clearly that's what I have to do next. Any embedded developer would know how to do that, so maybe there's no point in dumbing it down so much with a gui like this, and then inevitably failing anyway? Or at least plan on a workaround being available.