input: 
  def generate_fibonacci(n: int) -> str:
      """ Generate a string containing the Fibonacci series up to the given number n.
      The output will be a comma-separated string of numbers from the Fibonacci sequence.
      Each number in the sequence is the sum of the two preceding ones.
      
      >>> generate_fibonacci(5)
      '0, 1, 1, 2, 3'
      >>> generate_fibonacci(10)
      '0, 1, 1, 2, 3, 5, 8, 13, 21, 34'
      """
  
output:     if n <= 0:
          return ""
      if n == 1:
          return "0"
      
      fib_sequence = [0, 1]
      while fib_sequence[-1] + fib_sequence[-2] <= n:
          fib_sequence.append(fib_sequence[-1] + fib_sequence[-2])
      
      return ', '.join(map(str, fib_sequence))