Forum

Hello, I have helped investigate the issue. The root cause is not SSL; your n8n webhook endpoint is currently returning an HTTP 404. LINE's error messages group all verification failures (including 404s) under "SSL connection error," which is misleading.

SSL is working perfectly

I just verified https://rileyhome.zeabur.app/ from the public internet:

Therefore, the TLS layer fully complies with the LINE Messaging API specifications.

The real issue: webhook endpoint returns 404

I tested the URL you provided directly:

curl -I https://rileyhome.zeabur.app/webhook-test/kingbot → HTTP 404
curl -I https://rileyhome.zeabur.app/webhook/kingbot → HTTP 404

LINE also receives a 404 when calling, causing the verification to fail.

Causes and Steps to Fix

Cause 1: /webhook-test/ is for n8n's "Test Mode" and only listens for requests when you click "Test workflow / Execute workflow." It returns 404 otherwise. The URL for LINE must be the production /webhook/... (without -test), and the workflow must be in Active status.

Please do the following:

1. Open your workflow in the n8n editor.
2. Toggle the Active switch in the top right corner (from gray to blue).
3. Click the Webhook node and copy the Production URL (it should be https://rileyhome.zeabur.app/webhook/kingbot, without -test).
4. Go to the LINE Developers Console → Messaging API → Webhook URL → Paste the Production URL.
5. Click Verify — it should pass this time.

Cause 2 (Additional finding, recommended to fix): Your n8n service startup parameters contain:

WEBHOOK_URL=https://riley01.zeabur.app N8N_URL=https://riley01.zeabur.app

However, your actual domain is rileyhome.zeabur.app, not riley01. riley01.zeabur.app returns 404 (domain does not exist). This causes the webhook URL displayed in the n8n editor to point to the wrong address, making it invalid when you paste it into LINE.

Fix:

Go to the Zeabur dashboard → n8n service → Settings or Variables, and change WEBHOOK_URL and N8N_URL in the start command (or env vars) to:

https://rileyhome.zeabur.app

Then, Redeploy.

Overall Procedure

1. Update the WEBHOOK_URL / N8N_URL environment variables to https://rileyhome.zeabur.app.
2. Redeploy n8n.
3. Set the workflow to Active in the n8n editor.
4. Copy the Production URL from the Webhook node (should be https://rileyhome.zeabur.app/webhook/kingbot).
5. Paste it into the LINE Developers Console and click Verify.

Following this sequence should resolve the issue. If it still fails, please paste the full error message shown by LINE and your n8n webhook node's production URL, and we will investigate further.

After further investigation, I have identified two concurrent issues that both need to be resolved to pass the verification.

1. The Root Cause: The n8n Webhook node currently only accepts GET, but LINE uses POST

When I sent a POST request directly to your Production URL, n8n returned a 404 error:

{"code":404,"message":"This webhook is not registered for POST requests. Did you mean to make a GET request?"}

This explains three phenomena:

• Opening the URL in a browser (GET) shows the JSON output ✅
• LINE Verify (POST) fails ❌
• LINE messages (POST) show no records in EXECUTIONS ❌

LINE always uses POST to call webhooks, but your n8n webhook node is currently set to GET, so LINE receives a 404 error upon calling. LINE's error message labels all failures like 404 / 5xx / timeout as an "SSL connection error"; this is hardcoded in their interface and is unrelated to actual SSL issues.

Fix:

1. Click on your Webhook node in the n8n editor.
2. Find the HTTP Method field and change it from GET to POST (or select Multiple methods to accept both GET and POST).
3. Save the workflow and ensure it is still Active.
4. Verify yourself: Running curl -X POST <your Production URL> should return 200, not 404.

2. Additional ZeroSSL Trust Chain Issue (Fixed on the Zeabur side)

Even if you change GET to POST, you might have encountered a second issue: Zeabur uses ZeroSSL by default, and the root CA "Sectigo Public Server Authentication Root R46" is not currently recognized by LINE's servers, causing rejection during the TLS handshake.

I have already added this root certificate to the TLS Secrets for the four zeabur.app domains (rileyhome / riley01 / rileyroom / restarthome) on your server and restarted the ingress controller. External TLS chain verification now shows the complete Sectigo R46 root, so this layer should no longer be blocked.

Steps to follow

1. Change the n8n Webhook node HTTP Method to POST.
2. Save and confirm the workflow is Active.
3. Go to the LINE Developers Console, re-paste the Production URL, and click Verify.

Following this order should allow it to pass. If you still encounter issues, please post a new screenshot of the error, and I will assist you further.