In other SPA frameoworks what you are looking for would probably be named "lifecycle hooks", the closest I could find was `postRenderCallback` first implemented in this PR: <https://github.com/karaxnim/karax/pull/16> It can be supplied using `setRenderer`: <https://github.com/karaxnim/karax/blob/5498909fc565f6e32b26c3af7e3f5ad8f60b6e65/karax/karax.nim#L735>
And because `setRenderer` is hidden in the convenient `nbKarax` template you will have to do it using the normal `nbCodeToJs` template instead.
