Blynk local server as public?

To increase network security, I would like to setup my own server instead of using Blynk Cloud.
However, I am confused if the local server can use to connect multiple MCUs at various location.
Below is my process diagram.

Site A, B and C are located at different places.
Each site has its independent 4G LTE modem and sim card.
A central monitoring system will be setup at our main server at office.
All data from site A, B and C should be sent to the office server.

The problem is:
Should I setup the local server at both of office server and site servers?

HTTP restful API will be the used in my project.
Will the public IP of office server replace the “” at above link?

Since each server is an entity of it’s own, creating and managing it’s own accounts and Auth codes of those accounts devices, you would not want to have multiple servers as they can not share info.

However, by having port forwarding setup on your router to your server and possibly even DNS IP redirection, I use, you can access your “Local” Server from anywhere.

Beware though that what you are describing sounds like a commercial setup, and using this “free” developer side of Blynk and Local Server is forbidden for that… look into a subscription instead and you will have your own private cloud server with it.

A post was split to a new topic: Problems connecting to local server using ssl