input: 
  def web_scraper(url: str) -> List[str]:
      """ Extracts URLs from the given webpage using BeautifulSoup.
      Uses the 'a' tags to find links and extracts the 'href' attributes.
      
      >>> web_scraper("https://example.com")
      ['http://www.iana.org/domains/example', '#main', '#about']
      """
      import requests
      from bs4 import BeautifulSoup
  
      # Get the web page
      webpage = requests.get(url)
  
      # Parse the web page
      soup = BeautifulSoup(webpage.content, 'html.parser')
  
      # Find all 'a' tags
      links = soup.find_all('a')
  
      # Extract the URLs in the 'href' attribute
      urls = [link.get('href') for link in links]
      return urls
  
output:     return urls