Human In the Loop with Slack

Questions
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1

Describe the problem/error/question

I am trying to integrate the Slack node as a way to approve some process... I can't get the slack node to successfully return the approval result. Everything works up to when I click the response in Slack and the n8n flow is supposed to continue. I get a warning on Slack that says 'This app responded with Status Code 404' and node in n8n only shows a Loading Data message with a spinner and stays that way.
I know that in The Slack app configuration I have to set the Request URL but to what? I cant find where in n8n is this url provided.

Screenshot 2026-04-05 at 16.59.30
Screenshot 2026-04-05 at 16.59.302826Ă—1778 272 KB

What is the error message (if any)?

Please share your workflow

Share the output returned by the last node

Information on your n8n setup

2

Hey! Your workflow looks fine, the issue is in your Slack app config. You need to go to your Slack app settings at api.slack.com, then go to “Interactivity & Shortcuts”, turn it on and set the Request URL to https://<your-instance>.app.n8n.cloud/rest/waiting-webhook/ — replace <your-instance> with whatever your actual n8n cloud subdomain is. The 404 is just Slack not knowing where to send the button click payload, once that URL is set it should flow right back into n8n and continue the execution.

3

Thanks. It is working now. I had those urls confused.