Attention everyone. I’m not planning to make any more improvements to my add-ons. I’m moving to native docker, so it will be hard to support them going forward. There are other node-red add-ons available that you can use. It looks like Home Assistant Community Add-on: Node-RED is the best alternative.
I realize there was a change to hassio supervisor 118 that broke the API proxy. Switching to your connection to use your public hostname instead of http://hassio/homeassistant should workaround the issue until there is a permanent fix.