Thanks for the feedback, it is really valuable.
Sorry for the inconvenience with the forum, glad you pushed it trough.
Etcher uses the same library for the admin prompt for quite some time, however macOS changes.
I guess since you don’t want to enter your password there you were not able to complete the flashing.
We will update this part as soon as possible.
If you downloaded etcher from balenaEtcher - Flash OS images to SD cards & USB drives or the github repo you should be good to go.
Other option is to start etcher already as admin, so it won’t ask for password during the process.