Describe the problem/error/question
I seem to have an issue that I haven’t seen anyone else deal with yet 
. I’m unable to connect to Google OAuth (get my credentials connected to n8n). I have: setup the scopes, added myself as a test user (same email), made it external, tried production & testing mode, and created the client & transferred the key & secret, all with no success. (and also have the Google sheets API)
What is the error message (if any)?
When i’ve filled out the credential form (for Google sheets, on n8n) and get prompted to sign in to google I get “Access blocked: Authorization Error”. No other options to click on, just that popup.
I am assuming there is a problem with the Authorised redirect URL. For client IDs i have both:
http://localhost:5678/rest/oauth2-credential/callback & https://************.ngrok-free.app/rest/oauth2-credential/callback (i also setup Ngrok thinking local hosting was messing it up). n8n has gives http://1.1.1.1:5678/rest/oauth2-credential/callback as a redirect, which isn’t even accepted as valid by Google so that makes things more confusing as well.
It makes me think that there is not a problem with the connection to Google but rather something else? Im pretty lost, been troubleshooting and browsing forums for hours. 
Information on your n8n setup
- n8n version: Updated Sep 7, 2025
- Database (default: SQLite):
- n8n EXECUTIONS_PROCESS setting (default: own, main):
- Running n8n via (Docker, npm, n8n cloud, desktop app): Docker
- Operating system: Mac OS
