invalid client - google-auth-library even when client id is correct

Question

I'm using google-auth-library in nodejs

Everything was working fine. until for some reason my one of the domain is down. api.example1.com

and in google console the redirect uri was ->
https://api.example1.com/google/cb there was nothing special in that route since I'm already getting the

auth_code from client like -> React, Android

import { useGoogleLogin } from "@react-oauth/google";

so I've just created another server with same code on the api.example2.com and I've also added this in the authorized redirect urls.

but unfortunately. it giving error even though

CLIENT_ID and CLIENT_SECRET are correct.

This is Error I Got

{
"error": "invalid_client",
"error_description": "Unauthorized"
}

const oAuth2Client = new OAuth2Client({
  clientId: process.env.GOOGLE_CLIENT_ID,
  clientSecret: process.env.GOOGLE_SECRET_ID,
  redirectUri: process.env.REDIRECT_URI,
});

Usage

const { tokens } = await oAuth2Client.getToken(code);

Answer 1

Over Confidence is not a good thing.

You may think that every credential is valid but that is not the case.

In my case my CLIENT_SECRET was different.

so double check if possible triple check every credential for this error. invalid_client

{
  "error": "invalid_client",
  "error_description": "Unauthorized"
}