How to blink led by communicating between master and slave using module RS485

Hi everybody
Sorry for using Google Translate, I'm from Vietnam
I have a device control project that includes turning lights on and off between master and slave. My master uses esp8266 and my slave uses arduino nano. Between Slave and Master communicate via RS485 The console is the blynk app. All my equipment is on the Slave side. Currently, I don't know how to write code for master or slave. Please everyone help me.

Have you looked for some code online, for example:

https://www.gammon.com.au/forum/?id=11428

You may have to adapt the examples for an ESP8266