People counter keeps counting add LEDs

Hi,
I am working with a visitor counter and how can I add LEDs to my project? For example, I want a green LED to light up when you enter, how can I do it?

int trig = 10;
int fan =8;
int echo = 9;
int led = 7;
int buzzer= 6;
int i=0;
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() 
{
   lcd.begin(16, 2);
  Serial.begin(9600);
  pinMode(trig,OUTPUT);
  pinMode(echo,INPUT);
  pinMode(led,7);
  pinMode(fan,8);
  pinMode(buzzer,OUTPUT);
  lcd.setCursor(4,0);
  lcd.print("Welcome");
  delay(2000);
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Please wait.");
  delay(200);
  lcd.setCursor(0,0);
  lcd.print("Please wait..");
  delay(200);
  lcd.setCursor(0,0);
  lcd.print("Please wait...");
  delay(200);
  lcd.setCursor(0,0);
  lcd.print("Please wait....");
  delay(200);
  lcd.setCursor(0,0);
  lcd.print("Please wait.....");
  delay(200);
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Please wait.");
  delay(200);
  lcd.setCursor(0,0);
  lcd.print("Please wait..");
  delay(200);
  lcd.setCursor(0,0);
  lcd.print("Please wait...");
  delay(200);
  lcd.setCursor(0,0);
  lcd.print("Please wait....");
  delay(200);
  lcd.setCursor(0,0);
  lcd.print("Please wait.....");
  delay(200);
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Please wait.");
  delay(200);
  lcd.setCursor(0,0);
  lcd.print("Please wait..");
  delay(200);
  lcd.setCursor(0,0);
  lcd.print("Please wait...");
  delay(200);
  lcd.setCursor(0,0);
  lcd.print("Please wait....");
  delay(200);
  lcd.setCursor(0,0);
  lcd.print("Please wait.....");
  delay(200);
  lcd.setCursor(0,0);
  lcd.print("Please wait.....");
  delay(200);
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Visitor Counter");
    lcd.setCursor(1,1);
  lcd.print("By Thunder");
  delay(2500);
  lcd.clear();
}

void loop() {
  lcd.setCursor(0,0);
  lcd.print("People visited:"); 
  digitalWrite(trig,LOW);
  delayMicroseconds(5);
 
  digitalWrite(trig,HIGH);
  delayMicroseconds(10);
 
  
  digitalWrite(trig,LOW);
 
  
  int a = pulseIn(echo,HIGH);
 
  
 int distance = a*0.034/2;
  
  

  if ( distance<40) //in
  {
  i=i+1;
    delay(500);
    digitalWrite(buzzer,HIGH);
    delay(100);
    digitalWrite(buzzer,LOW);
    delay(100);
   
     lcd.clear();
    lcd.setCursor(0,0);
  lcd.print("People visited:"); 
    lcd.setCursor(0,1);
  lcd.print(i);
    delay(400);
  
  }
   if ( distance>60) //out
  {
  i=i-1;
    delay(500);
    digitalWrite(buzzer,HIGH);
    delay(100);
    digitalWrite(buzzer,LOW);
    delay(100);
     lcd.clear();
     lcd.setCursor(0,0);
  lcd.print("People visited:"); 
    lcd.setCursor(0,1);
  lcd.print(i); 
     delay(400);
    
  }
 
}

My project is there ;
image

the above will be true presumably as long as the person is in the room (within range), not just when entering the room.

keeping track of the previous distance would allow recognizing when there is a change in distance indicating a person entering the room, incrementing a count (i++) and turning on an LED.

similar logic can be added to track a person leaving

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