Hi!
With multi-step forms, the need to change the forms base domain is pretty much a necessity because they use the webhooks base domain to send requests to /form-waiting. Because of this, if you use a reverse proxy, or something like Cloudflare One, allowing only access to authenticated users on the main n8n domain, but need webhooks to be public, you generally configure a different domain allowing public access only to the /webhook path. For our usecase, forms are used as internal tools, which should not be public. Thus, access to them is only allowed through the main n8n domain, which is secured by Cloudflare One. Things work with simple forms, because I can simply change the domain to the main one and voila. But with multi-step forms, the request to /form-waiting is made to the webhook base domain, even if I’m on another domain. This raises CORS issues, which is not configured in the /form-waiting response, as well as a difficulty to configure auth.
I see this was already requested in Customize N8N Form URL base domain, but the situation changes with multi-step forms. Either the forms base domain should be customizable, or the form should make the request to /form-waiting on the same domain that it’s being accessed from.
Here to help.
Thanks!