PKCE verification

code=e20a178b-4dc6-41f4-a5bb-67bc7d41e17e.949c482a-c5e7-4e65-ad46-2e839661046e.d96960b1-91ae-47ba-8a8d-0c1f5fc9ed4d&grant_type=authorization_code&client_id=igss&redirect_uri=https%3A%2F%2Fwww.example.com%2F&code_verifier=w0C9yDCQXGqvLgP3JT5Aff6bVpjCB89ZjhH5cAeZ1vOPVZH96qnDDA6qubpEcddnS89e9zGMAwsbu81K4pZUMG9JPgmcA0fp

Please i need help to solve this … i try to use OB to generateAuth0verifier but not working.
i keep getting this result {“error”:“invalid_grant”,“error_description”:“PKCE verification failed”}