code: def find_pingback_href(self, content):
          
          soup = BeautifulSoup(content, 'html.parser')
          for link in soup.find_all('link'):
              dict_attr = dict(link.attrs)
              if 'rel' in dict_attr and 'href' in dict_attr:
                  for rel_type in dict_attr['rel']:
                      if rel_type.lower() == PINGBACK:
                          return dict_attr.get('href')
docs: Try to find LINK markups to pingback URL.