JAVA_OPTS="$JAVA_OPTS -javaagent:/path/to/plumbr.jar"

When everything went smoothly, you will see the following banner in the restarted JVM standard output and a new JVM appears in https://app.plumbr.io.

************************************************************
* Plumbr (15.01.4138) is attached.                         *
*                                                          *
* Plumbr agent is connected to the Plumbr Server.          *
* Open up https://app.plumbr.io to follow its progress. *
************************************************************