You can set a single
fallback redirect URL on each custom domain. It covers two cases:
- Someone visits the domain on its own - for example
app.yourdomain.com with nothing after the slash. - Someone visits the domain with a slug that doesn't match any of your Onelinks - for example a mistyped or deleted link like
app.yourdomain.com/oldcampaign.
In your account dashboard, under Custom Domains, set a destination URL for the domain (such as your homepage or a generic landing page). Visitors in either case above will be redirected there automatically.
If you don't set a fallback URL, those visitors see the default page instead. The destination must be a full
http or
https URL, and it can't point back to the same custom domain (to avoid redirect loops). Valid links continue to resolve to their configured destinations - the fallback only applies when there's nothing to serve.