Backend is Laravel with Blade templates, can we use Croct without a JS framework?

You are covered, no JS framework needed. There is a dedicated PHP SDK, and the docs have specific pages for Laravel, Symfony, and Drupal on top of the generic PHP one. You fetch the slot content server-side in your controller and pass it to the Blade view like any other data, so the rendered HTML already carries the personalized content.

Two details worth knowing:

• The CLI generates a slots.stub file for PHP projects, which is the equivalent of the slots.d.ts file TypeScript users get. Your IDE picks up the slot content shapes from it.
• If you later want client-side event tracking (clicks, custom goals), you can drop in the script tag or the JS SDK alongside the server-side fetch. They work together fine, the server does the rendering and the client does the tracking.

We run a similar Laravel setup and never touched React for it.