Alternative solution to two pointers is using a stack, which is a Last In First Out data structure. Since the last vowel in the original string will be the first vowel in the new string, I chose to use a stack. Here's how I did it:

class Solution:
  def reverseVowels(self, s: str) -> str:
    vowels = 'aeiouAEIOU'
		vowelStack = [] # Create an empty stack
		newString = ''

    for c in s:
      if c in vowels:
        vowelStack.append(c) # Push vowel onto stack
    
    for c in s:
      if c in vowels:
        newString += vowelStack.pop() # This is where vowels are reversed
      else: newString += c

    return newString