Check_MK Discovery Can not load Robotmk JSON data! (json.loads())

Hello.

I’m running into a similar issue as this one.
I’m setting up the tests on a Linux Ubuntu machine, and I believe I’ve successfully installed the agent with the Robotmk plugin. In the folder “/usr/lib/check_mk_agent/plugins” I have the “robotmk-runner.py” file.
I was also able to test the Robot Framework and it runs tests successfully by hand on the console.

So first, I don’t know where to put the test files. All articles that mention this folder (which is “robot”) are run on Windows and the structure is not the same in Linux. I’m not sure if it should also use the “robot” folder, but this folder is not created initially anywhere. I have two different folders called “check_mk_agent” in different paths and tried to create the “robot” folder in one of them, and placed the test files in there. But it doesn’t seem to be running anything.
Placed it at “/usr/lib/check_mk_agent/”.
The other possible folder is "/var/lib/check_mk_agent/

As you can see below, I get the error message on the Checkmk monitoring for this agent, and not on the test run logs as I don’t have any (maybe this is the reason for the error).

jtc@ubuntu-client:~$ robot --version
Robot Framework 6.0.1 (Python 3.10.6 on linux)
jtc@ubuntu-client:~$ cmk-agent-ctl --version
cmk-agent-ctl 2.1.0p15

Can anyone shed some light? Or point to a document that shows how to set it up in Linux?

Thank you.