Searchkit is able to do server side rendering with a few changes. Due to elastic-ui isn't SSR friendly, you will need to build your own components to do SSR. The first part is to configure apollo to be able to SSR. See Apollo Server side rendering guide. Take note on the uri, you will need it to be an absolute path instead of a relative path.
Then you must enable url synchronization.
An example of the configuration can be seen below. You can see it in action here
See SEO tips for more information on how SSR and other features can improve SEO on your search.