How connect different external device to home assistant

Good morning everyone,
I’ll briefly explain my scenario: I have HA at home connected with different Arduinos and ESP32s connected with mqtt, I use cloudflare to reach the HA interface. I also have a box far from home connected to the internet with an LTE router, where I have an Arduino and a webcam. I need to understand if I can use Cloudflare to make the Arduino communicate with the main HA. Can you give me some advice?
TY