Failed upgrade

I’ve had my docker hassio setup for several months now, and all was fine until this morning when I attempted to upgrade and there was an internet failure. When the internet is up and running again, Home Assistant will not start properly. What I would like to do is to restart that upgrade process, and looking at https://www.home-assistant.io/hassio/installation/ under " Run a specific version on Hass.io", I could possibly use the “hassio” command to do so, but I cannot find this command in the docker containers (home assistant or supervisor container). Can someone tell me where I can access this command, either from the host or docker container? Any other suggestions to get back and running would be greatly appreciated.