Move some sensor data over internett securly with mqtt

Configuration
1

Hi, I have been trying to find som sort of way to may sensor data between two instanses of home assistant over the internet.
My initial thouth is to use mqtt in order to minimize the amount of data. ( I have limitations). on the slave system I will rund the automations localy, but there are some data, like temperature and door switches that I would to transmit to a master system.

Is there a guide out there that explains how to move data over the internett securly between two home assistanses with MQTT?

2

Scroll down to Managed MQTT Servers/Brokers- Cloud Hosting.

3

There’s a custom component that does this to consider.