I see you are using 8080 to server index.html but your jwt is probably on 3030, while that does not make any difference, just ensure local jwt is running.
You will not be able to open the link http://localhost:3000/api/users/sts as is. It is not a supposed to be a get method call and needs a payload.
Please go through all the links presented and do step by step. Use the documentation link in point 1.
What this means is that the client id and secret you are using are not the ones from the app that is published (assuming) with the bot’s web/mobile channel.
You will need to ensure same client id, secret, botid combination is used and it is in sync with bot’s channel and web-sdk. Also publish is important.
I see you are using 8080 to server index.html but yourJWT is probably on 3030, while that does not make any difference, just ensure local JWT is running. In case you want to obfuscate your client id and secret and not expose it to users, you can refer to this update below thread. It’s really a nice and helpful dissertation writing services piece of information. I’m glad that you shared this helpful info with us.