After intense searching, I now realize (after having bought the Nano Every for 12 different schools -- many which are solely on Chromebooks) that the Nano Every is not supported with the Web Editor on Chromebooks. It's not on the list of supported microcontrollers: https://support.arduino.cc/hc/en-us/articles/360014779899-Which-boards-can-be-used-with-the-Arduino-Create-Chrome-App-
And, it looks like others are in a similar boat, e.g. Nano Every not working with Create Chrome app
Given this is a low-cost and powerful microcontroller that schools are likely to purchase (one of the few that Arduino.cc sells in a pack), it's unfortunate that it's not supported on Chromebooks.
What needs to happen to add this board to the supported list?
Thanks,
Eric