Hey @midja, welcome to the community!
I am sorry to hear you’re having trouble here. The desktop app uses a special tunnel to allow external webhooks to send data to your n8n instance (which is usually not possible). This tunnel connection can unfortunately break (for example when your network connection is interrupted). @ivov shared some more technical details on this tunnel over here.
tl;dr a webhook URL of https://{adjective}-{noun}-{number}.hooks.n8n.cloud/rest/oauth2-credential/callback indicates a problem with the tunnel.
Is this by any chance the URL you are seeing? If so, you’d need to remove the existing tunnel subdomain. If you are on Mac OS this can be done by closing the desktop app, opening the ~/.n8n/config file and removing the tunnelSubdomain line and the comma in the line above, making sure it’s valid JSON when saving the file.
Before:
{
"encryptionKey": "123abc456",
"tunnelSubdomain": "123abc456"
}
After:
{
"encryptionKey": "123abc456"
}
Now when restarting n8n desktop it should register a new tunnel URL. On Windows the required config file would be in the C:\Users\<username>\.n8n directory.
Hope this helps! Let me know if you run into any trouble with this.
On a side note, if you plan to use n8n for reliably processing form submissions even when your desktop computer is switched off or not connected to a network, you might want to consider hosting n8n on a server (this requires some initial effort to set up) or using n8n.cloud. Both options would mean you don’t have to deal with a possibly unstable tunnel.