How I solved

I wanted to implement third party signin option for my webapp.

Since my app runs on NodeJS, PassportJS was the obvious choice. I have already made local signin work, and I thought configuring third party signin options should not be too hard. But I was stumped for two hours, trying to figure out how to solve InternalOAuthError: Failed to obtain request token.

Even if I followed PassportJS Doc or guide from Scotch.io, I kept on getting the error. I had initially thought it was express-session not configured correctly. But Google’s official API console help stated: OAuth 2.0 client IDs.

Using OAuth2.0 worked instantly.