Prints data to the transmit pin of the SoftwareSerial object as raw bytes. Works the same as the Serial.write()function.
mySerial.write(val)
The number of bytes written (reading this number is optional).
#include <SoftwareSerial.h>
// Set up a new SoftwareSerial object with RX in digital pin 10 and TX in digital pin 11
SoftwareSerial mySerial(10, 11);
void setup() {
    // Set the baud rate for the SerialSoftware object
    mySerial.begin(9600);
}
void loop() {
    // Send a byte with the value 45
    mySerial.write(45);
    //Send the string “hello” and return the length of the string.
    int bytesSent = mySerial.write(“hello”);
}