@bwpbruce
There’s no Etcher packages for Chrome OS.
If your chromebook has an intel or amd processor and supports running Linux apps, you may be able to install the deb package from here https://github.com/balena-io/etcher/releases/download/untagged-174cb367c86f54c5229f/balena-etcher-electron_1.5.28_amd64.deb using these instructions https://www.androidpolice.com/2018/08/08/chrome-os-canary-can-now-install-linux-apps-deb-packages/ .