Which port should I use?

Your ports can be found in the control panel for your instance. On dedicated plans, it's possible to change ports. Available ports are

• Plain MQTT
• MQTT over TLS. More information can be found at https://www.eclipse.org/paho/clients/python/docs/#tls-set
• MQTT over Websockets over TLS. Can be used to connect to the broker directly from a website using javascript. More information can be found at https://www.eclipse.org/paho/clients/python/docs/#tls-set