OK I finally got this working. In my travels I ran across portainer. I viewed the container details, and the frappe_site_name_header was called “frontend”.
I used your command but modified:
docker compose exec backend bench set-url-root frontend https://myserver and the Redirect URI changed to https://myserver.
I understand the commands, but I don’t understand why the site_config.json located in /var/lib/docker/volume/frappe_docker_sites/_data/frontend which is listed above with correct syntax did not work. Clearly it has to be running under “frontend” as your command worked with that name. To that end I am unclear as to why it is using “frontend”.
Maybe someone with more docker linux experience can explain to me what the hell is going on.