From the information in the screenshot I saw that the machine with HARK installed appeared to be separate from the machine it was working on, making a remote connection. If you have a remote connection, please try the following steps.
The behavior when no options are given to the hark_designer command is to start the HARK-Designer server, then start the browser and connect as a client. That is, it tries to boot for use on the local machine.
When making a remote connection, it is necessary to start up only the HARK-Designer server, so it is necessary to start it as follows.
If port number 3000 is not available (for example, another application is using it), you need to change the port number.
If you need to change the port number used to connect HARK-Designer from the initial value of 3000, give the environment variable as follows and start hark_designer.
If you want to set the port number to 4000:
PORT=4000 hark_designer allowremote
After the server is up, launch a browser (Firefox, Chrome, etc.) on the machine you are working on and connect to the machine where HARK is installed.
If the port number is 4000 and the IP is 126.96.36.199 then: