The code that you’ve linked to on the GitHub site contains no Blynk libraries or code, and doesn’t have any features other than outputting the readings to the serial monitor.
It also contains this function call in the void loop…
but there is no void sei() in the .ino file or the accompanying .h files.
Hence my question (which remains unanswered)…
Personally, I doubt that that is true, but you really ought to be using a different Modbus library.
You probably ought to be using different hardware too - something with in-built IoT connectivity.
I use Modbus to read data from my solar charge controllers, and push the data to Blynk.
I’d start by reading this if I were you…
Then look at other topics relating to epever devices.
Pete.