looking for an optimal solution to finding pairs in an array base on certain condition in Javascript

Question

loop through an unsorted array and find pairs whose sum of those two pairs is equal to the target, for instance an array like: [1, 2, 4, 3, 7, 6, 2, 1, -4] and target is equal to 5

function findPairs(array, goal) {
  // implement your optimal solution here!
  return [];
}

findPairs([1, 2, 4, 3, 7, 6, 2, 1, -4], 5);

I solved it with two nested for-loops which is not an optimal solution because the nested loop's complexity is O(n²).