Cannot connect to SmartThings

Hi, Sorry am new to this and tried to connect Home Assistant (running in a docker container) to connect to SmartThings but even after following the instructions as outlined here, I get the following error.

I am not using Home Assistant Cloud (Nabu Casa) but trying with the Web Book, and I do have the port forwarded. So how can I format the URL to not get this error.

For example if I have something like http://mysite.com:8123 and my SmartThings token as 12345678-1234-1234-1234-123456789012 - how / what format do I enter it?
Screenshot%20from%202019-10-05%2019-47-03
Thanks,
Amit.

Is your https entry in the configuration yaml accessible externally to your network?