There are sitmap plugins for October CMS that you can use, and that is ok. The problem with that is that they mostly support only Pages, Static Pages and Blog plugin out of the box. For any other model on your site you would have extend that plugin to recognize your custom model.

So that is one way you could tackle the sitemap problem. The other way, that I will show you in this video is to create a Route that will return a view with XML sitemap. I think that by doing this you have much more control over how your sitemap will look.

Icon in the video made by Freepik from www.flaticon.com is licensed by CC 3.0 BY