code: def activation(self, activation_hash):
          
          reg = self.appbuilder.sm.find_register_user(activation_hash)
          if not reg:
              log.error(c.LOGMSG_ERR_SEC_NO_REGISTER_HASH.format(activation_hash))
              flash(as_unicode(self.false_error_message), "danger")
              return redirect(self.appbuilder.get_url_for_index)
          if not self.appbuilder.sm.add_user(
              username=reg.username,
              email=reg.email,
              first_name=reg.first_name,
              last_name=reg.last_name,
              role=self.appbuilder.sm.find_role(
                  self.appbuilder.sm.auth_user_registration_role
              ),
              hashed_password=reg.password,
          ):
              flash(as_unicode(self.error_message), "danger")
              return redirect(self.appbuilder.get_url_for_index)
          else:
              self.appbuilder.sm.del_register_user(reg)
              return self.render_template(
                  self.activation_template,
                  username=reg.username,
                  first_name=reg.first_name,
                  last_name=reg.last_name,
                  appbuilder=self.appbuilder,
              )
docs: Endpoint to expose an activation url, this url
              is sent to the user by email, when accessed the user is inserted
              and activated