Using a 3x4 matrix keypad with I2C LCD

Thank you would you know how to code this i have most of the code typed up i just need it to print something on the LCD when i hit the number i have in my loop to readKeypad() and the fuction readKeypad() is as follows

void readKeypad()
{
char key = keypad.getKey();
if (key != NO_KEY)
{
switch(key)
{
case '*':
z=0;
break;
case '#':
delay(100); // for extra debounce
checkPIN();
break;
default:
attemptC[z]=key;
z++;
}
}
}

I would like to somehow put in that function if i type in a 1 and a 2 into the keypad the LCD prints "turn on red LED?" and i would have to hit the "#" button to turn on the red led function.