Webthing addon with java

I wanted to download & run mocked web thing and connect it to my server set on raspberry pi. Firstly I downloaded sample code from below repository and run this app, then I tried to connect it by webthing addon. Unfortunately, it cannot connect and after further investigation, I still don’t know why. I used following url to connect it to my app:
where is my internal ip, and 8888 is the port on which I run my application. The host on which I run my app is mac big sur, webthing server I have set on raspberry pi.

What is done incorrectly in the following statement? Please find me as a beginner, not only in Webthings but also in computer science, therefore I understand that reason can be trivial and obvious for some of you.

Hi Michal, welcome.

Are you able to connect to your mocked device using another means in order to debug it?

The curl-example repository provides some examples of how to communicate with a device using the curl command line tool.

Postman is a useful graphical tool for composing and sending HTTP requests.

You can also open developer tools in Firefox/Chrome by pressing F12 and inspect the HTTP requests going back and forth in the Network tab to look for errors.

I recommend using Postman.

You could start by sending a GET request to your thing URL ( and see whether it responds with its thing description. You’ll need to set an “Accept” header to “application/json” in your HTTP request to tell the web thing server that you would like a JSON response.

Thank you for your advices. My problem was noob worthy, it was connected with a security issue on my company computer. Please forgive me for making unnecessary troubles.