Skybrud Redirects doesn't work with Umbraco's content delivery - at least not directly.
Umbraco's content delivery works the way that you can request a content route specifically, or a media route specifically. There isn't an endpoint for specifying a generic route, and then determining from the response whether the route represents a content or media item - or an external redirect. Umbraco's content delivery API also doesn't offer a good away to handle redirects within the content and media endpoints.
So for this to work, there are a few ways you could go instead:
Approach 1
1. look for the route via the content/media endpoint
2. if not found, look for a redirect matching the route
- this isn't supported by Skybrud Social, so you'd have to create your own endpoint for this
This could potentially be 2-3 requests between the frontend and backend, so an alternative could be:
Approach 2
1. create a custom endpoint that takes the route as a parameter
1. check if a content node exists with the route
2. check if a media exists with the route
3. check if a redirect exists with the route
This will then be a single request between the frontend and backend, but require you to implement more code on your own.
Approach 3
If you have some kind of middleware between your frontend and backend, you could also create a custom endpoint that lists all redirects, and then cache those within the middleware. But with caching, there should also be a way to invalidate the cache - e.g.: if a user creates or updates a redirect.
Anyways - Skybrud Redirects doesn't offer a content delivery API on it's own. Primarily because I hadn't needed this my self, and you're only the second person to ask about this. But also because - as described above - there isn't just one way to go about this.