All the documentation claims that this would be a fairly straightforward task, but each time I try I receive the following error:
Configurator could not perform the requested action because "iPad" has already been prepared.
Each time I choose "Erase" and attempt again, but I get the same error. I can't seem to find any discussions RE: this specific error on Apple or Jamf boards, so I'm hoping someone else has troubleshot this one before.
Have you tried putting your device into Recovery Mode before attempting supervision? If not, follow the instructions here.
If so, it is worthwhile to try placing the device into DFU mode and trying again. I've seen this happen sometimes and a DFU restore will generally resolve the issue.