Are you using Arduino core on your ESP8266 or are you using NodeMCU Lua? They are completely different firmwares; Arduino core uses cpp and has many libraries that parallel functionality to an AVR Arduino board like the Arduino Uno. NodeMCU uses Lua script.
I use softwareserial and ive heard that it work but dont really know.
There is a SoftwareSerial for the ESP’s Arduino core, but I have never attempted to use it. Both SensorModbusMaster and YosemitechModbus are completely independent of SoftwareSerial. They should work on an ESP8266 using Arduino core, but, again, I’ve never tried.
As i couldnt download his code i made it from scratch.
I have no clue what code you’re talking about.
Acording to how i connected it it seems like its connected to the nodemcu but actually i dont really know sadly
Well, does it communicate or not?