Very Confused on Nesting For Loops

I’m kinda confused by the challenge on what it’s trying to ask me to do and what I should do. I didn’t change much but I don’t know where to go about with this.

function multiplyAll(arr) {
  var product = 1;
  // Only change code below this line
  for (var i = 0; i < arr.length; i++) {
    for (var j = 0; j < arr.length; j++) {
      product += arr[i][j];
  // Only change code above this line
  return product;

// Modify values below to test your code

Link to the challenge:

You need to re-read the instructions. You are supposed to multiply the values together. What is your code actually doing? Adding them.

  product += arr[i][j];

Do you see where the problem is?