Myopenhab not reachable

So this still works, just to be clear.

Your openHAB instance has a REST interface that is available through myopenhab using HTTP Basic auth (and your myopenhab username password) so you could have something update an item externally , for example using curl (command line http client) i can trigger a switch to “ON” like:

curl  -u username:password -H "Content-Type: text/plain"  -X POST -d "ON"  https://myopenhab.org/rest/items/TestSwitch

Some systems may also use this format for auth, as long as they can send a POST command to a URL:

https://username:password@myopenhab.org/rest/items/TestSwitch

Just be careful exposing your system like this.

Does that help?