code: def clean_redirect_uri(self):
          
          redirect_uri = self.cleaned_data.get('redirect_uri')
  
          if redirect_uri:
              if not redirect_uri == self.client.redirect_uri:
                  raise OAuthValidationError({
                      'error': 'invalid_request',
                      'error_description': _("The requested redirect didn't "
                          "match the client settings.")})
  
          return redirect_uri
docs: :rfc:`3.1.2` The redirect value has to match what was saved on the
              authorization server.