That is if pm2 is watching the script files for change. Its mainly for developers to have pm2 reload the script if it gets updated. I do not use that
If you want to use the Panel you will have to add it in the Process tab. Then go to the RPi ip address and the port you assigned to the Panel.
The application is collect and storing the data. If you want to view it you will need to use a SQL application. You will connect to the RPi ip address on port 3306. I use a program called Sysyog. You can use any MySQL editor available for your computer OS.