code: def retrieve_matching_jwk(self, token):
          
          response_jwks = requests.get(
              self.OIDC_OP_JWKS_ENDPOINT,
              verify=self.get_settings('OIDC_VERIFY_SSL', True)
          )
          response_jwks.raise_for_status()
          jwks = response_jwks.json()
  
          # Compute the current header from the given token to find a match
          jws = JWS.from_compact(token)
          json_header = jws.signature.protected
          header = Header.json_loads(json_header)
  
          key = None
          for jwk in jwks['keys']:
              if jwk['kid'] != smart_text(header.kid):
                  continue
              if 'alg' in jwk and jwk['alg'] != smart_text(header.alg):
                  raise SuspiciousOperation('alg values do not match.')
              key = jwk
          if key is None:
              raise SuspiciousOperation('Could not find a valid JWKS.')
          return key
docs: Get the signing key by exploring the JWKS endpoint of the OP.