Problems using Serial AT Commands and the SIM800L GSM Module

I am using the following SIM800K GSM Module

I have tried many different tutorials eventually arriving at the following one that seems to allow me to test interactively using AT commands.

This code that I am using (on an Arduino UNO) is the following

#include <SoftwareSerial.h>
 
//SIM800 TX is connected to Arduino D8
#define SIM800_TX_PIN 8
 
//SIM800 RX is connected to Arduino D7
#define SIM800_RX_PIN 7
 
//Create software serial object to communicate with SIM800
SoftwareSerial serialSIM800(SIM800_TX_PIN,SIM800_RX_PIN);
 
void setup() {
  //Begin serial comunication with Arduino and Arduino IDE (Serial Monitor)
  Serial.begin(9600);
  while(!Serial);
   
  //Being serial communication witj Arduino and SIM800
  serialSIM800.begin(9600);
  delay(1000);
   
  Serial.println("Setup Complete!");
}
 
void loop() {
  //Read SIM800 output (if available) and print it in Arduino IDE Serial Monitor
  if(serialSIM800.available()){
    Serial.write(serialSIM800.read());
  }
  //Read Arduino IDE Serial Monitor inputs (if available) and send them to SIM800
  if(Serial.available()){    
    serialSIM800.write(Serial.read());
  }
}

I am guessing that AT commands are entered via the SEND field in the serial monitor.

No matter what I type into the serial monitor (pressing send) nothing new shows up in the monitor.

I am not sure what I am missing.

Not sure what I did but I got it to work