code: def create_le_verification_app(self):
          
          if self.LETSENCRYPT_VERIFY_APP_NAME in self._apps:
              logger.debug(
                  "The LE verification APP already exists as %s" % self.LETSENCRYPT_VERIFY_APP_NAME
              )
              verification_app = self._apps[self.LETSENCRYPT_VERIFY_APP_NAME]
          else:
              logger.info("Creating the identity-verification app for let's encrypt")
              verification_app = self.api.create_app(
                  self.LETSENCRYPT_VERIFY_APP_NAME,
                  'static_php70',
              )
              self._apps[self.LETSENCRYPT_VERIFY_APP_NAME] = verification_app
  
          # LE use the .well-known subfolder of the domain to do its verifications.
          # we will mount the app in the .well-known path, so we apply an hack to serve
          # the app-folder/.well-known on root
          app_root = os.path.join('~/webapps', self.LETSENCRYPT_VERIFY_APP_NAME)
          well_known_folder = os.path.join(app_root, '.well-known')
  
          if not is_link(well_known_folder):
              logger.info("Preparing static app for the verification")
              run('ln -s {app_root} {well_known_folder}'.format(**locals()))
          return verification_app
docs: Create the let's encrypt app to verify the ownership of the domain