No component compiled by astro() has been loaded.

RenderNotConfigured: renderToString() and renderToResponse() render components compiled by the astro() Vite plugin, and none has been loaded.

What went wrong?

renderToString() and renderToResponse() from @astrojs/runtime render components compiled by the astro() Vite plugin from @astrojs/vite-plugin-astro, which registers the renderers, client directives and component assets they need. No component compiled by astro() has been loaded in this environment, so there is nothing to render with.

To render components compiled without astro(), create a renderer with createRenderer() from @astrojs/runtime and use its renderToString() and renderToResponse().