Unauthorized error when connecting Facebook Lead Ads account

Questions
1

Describe the problem/error/question

Hi. I’m trying to connect the Facebook Lead Ads account (the only element in my workflow so far is a Facebook Lead Ads Trigger) to transfer leads to my CRM. To set up the account, I already did and double-checked:

  • Created the app in Meta
  • Added (correct) callback URL from n8n
  • Obtained advanced access for public_profile
  • Did verification, etc., that is necessary to take the app live and set it to “live”
  • Verified that pages_manage_metadata, pages_read_engagement, pages_show_list and leads_retrieval are “ready” for standard level
  • Added App ID and Secret to n8n
  • Clicked on Connect and selected everything
  • At the end of that Meta-Dialogue, it says that the app was connected and I can manage the connection via Facebook business apps. When I click on the final confirmation button, it opens the n8n callback URL with a “?code=…” attached to it. And there I see a simple JSON unauthorized error (see below)

I also tried to delete the account from n8n completely and remove the connection from the Facebook Business Apps to start fresh, but I get the same result.

Can anyone please give me a hint where I went wrong?

Thanks a lot.

Michael

What is the error message (if any)?

{“status”:“error”,“message”:“Unauthorized”}

Please share your workflow

Share the output returned by the last node

Information on your n8n setup

instance information

Debug info

core

  • n8nVersion: 2.13.4
  • platform: docker (self-hosted)
  • nodeJsVersion: 24.13.1
  • nodeEnv: production
  • database: postgres
  • executionMode: scaling (single-main)
  • concurrency: -1
  • license: enterprise (production)
  • consumerId: b14dff60-0166-47d7-95ff-2e9187c3efcb

storage

  • success: all
  • error: all
  • progress: false
  • manual: true
  • binaryMode: database

pruning

  • enabled: true
  • maxAge: 168 hours
  • maxCount: 10000 executions

client

  • userAgent: mozilla/5.0 (windows nt 10.0; win64; x64) applewebkit/537.36 (khtml, like gecko) chrome/146.0.0.0 safari/537.36
  • isTouchDevice: false

Generated at: 2026-03-30T15:22:14.796Z

3

Id double check that N8N_EDITOR_BASE_URL and WEBHOOK_URL in your docker config match exactly what you put as the callback in Meta, even a missing trailing slash or http vs https will break the oauth exchange silently.

4

Thanks to @Benjamin_Behrens and @achamm for their support. Indeed, the N8N_EDITOR_BASE_URL was not set at all in the Docker config (not sure what it defaults to then). After adding it this seems to work.