This is a snip of the vizualization opened on safari.
Link to the tutorial: https://mesa.readthedocs.io/en/stable/tutorials/adv_tutorial.html
This image shows the instructions.
I have tried the following: lsof -i : 8521 kill -9 PID #
But this dosen't work.
I also tried "ctrl + ." and it restarts the kernal but dosen't close the port and the vizualization.