As per
Properties you can override chapter of the plugin documentation you can set the Prometheus host and port via
user.properties file (lives in "bin" folder of your JMeter installation)
prometheus.ip=your-prometheus-ip-address-or-hostname
prometheus.port=port-of-your-prometheus-instance
or alternatively you can pass these properties via -J command-line arguments like:
jmeter
-Jprometheus.ip=your-prometheus-ip-address-or-hostname
-Jprometheus.port=port-of-your-prometheus-instance -t your-test.jmx
.....
More information: