Coin/Change Problem

1

Hi, I am white boarding on how to solve Coin/Change Problem. Given a set of coins (array of numbers) [1,2,3] find all the combinations that can add up to the given amount/target.
I understand the logic. The indexes of the array has to find all possible combinations, and so on.
I am having trouble with this can someone guide me through.
1,1,1,1,1
1,1,1,2
1,2,2
1,1,3
2, 3

 function coin(amount, array) {
  
  var results = [], result = [], total = 0;
  
  if (array.length === 0) {
    return results; 
  } 

  if ( amount <= 0) {
    return 'Enter an amount';
  }
  
  for (var i = 0; i < array.length; i++) {
    
 
    
    return coin(amount, array.slice(1));
  }
  
}

coin(5,[1,2,3]);