OAuth2 callback failed

I have a problem with Google: OAuth2.

I set up the Client ID and Client Secret. When I click on “Sign in with Google”, it is popping up the Google OAuth2 and I give it full access to my Gmail account.

After it’s redirecting me to my site (http://localhost:5678/rest/oauth2-credential/callback?state=eyJ0b2tlbi…), I get the following error:

Error: OAuth2 callback failed because of insufficient permissions

More detailsFailed to connect. The window can be closed now.

The same error in Chrome and Safari.

Please help.

  • n8n version: 1.67.1
  • Database (default: SQLite): SQLite
  • Running n8n via (Docker, npm, n8n cloud, desktop app): Docker
  • Operating system: Ubuntu 24.04

hello @Jeffrey

You should set the ENV variable WEBHOOK_URL . See docs.

but your site must have HTTPS protocol and use the 443 port to operate