Morse Code With for loop help needed

Other Hardware LEDs and Multiplexing
11

The code dot(2 ) calls the function dot and passes to it the value of 2.
In the definition of the dot(2 ) function their is a variable defined:-
int dot(int times){
It is that variable called times which is an integer that is set to the value of 2 from that call. However you don't actually use that variable so it is a bit useless in your code. I suspect you want to use it to set a number of repeats of the light flashing in that function. To do this you will have to use a for loop to repeat the light flashing.
Like

void dot(int times){
  for(int i=0; i<times) {
    digitalWrite(RedLED, HIGH);   
    delay(250);                   
    digitalWrite(RedLED, LOW);   
    delay(250);
  }
}

Note define the function as void, that means it does not return a value, and remove the return line because you are not doing anything with the returned value you have.

Make those changes in all your functions, and remove the for loop from the loop function, just leave its contents.