Leonardo Keypresses not working

Hello!

First, I'm new to this forum, so if I'm in the wrong board, please tell me.

So, a friend of mine made a No-Limits controller using a Leonardo board.
He gave me the code he uses and his wiring diagram.

I copied it exactly the same as he made it but, it doesn't work on my computer.

When I press a button the TX light blinks, and that's it.
I even tried uploading an example sketch to the board, but even that doesn't do anything.

When I changed keyboard.press('a'); to Serial.print('a'); it did show up.
Windows just doesn't seem to throw the key presses.

Does anyone have even the faintest of idea on what's wrong?

Many thanks!

Does anyone have even the faintest of idea on what's wrong?

No code
No schematic
No hardware details
No chance

Well, I said I'm new.
You could have just said I should've attached those.

#include "Keyboard.h"

const int buttonPin = 3;

void setup() {
  pinMode(buttonPin, INPUT_PULLUP);
  Keyboard.begin();
}

void loop() {
  
  int buttonPOS = digitalRead(buttonPin);

  if (buttonPOS == LOW) {
    Keyboard.press('a');
    delay(100);
    Keyboard.releaseAll();
  }
}

Arduino Leonardo, GND -> Button -> Pin 3.

(deleted)

You could have just said I should've attached those.

You could have read Read this before posting a programming question