Is it possible to embed a CMS into an already working one on Laravel?

Question

Laravel

There is a working site written in:
- Backend: PHP (Laravel)
- Frontend: JS (Vue.js) [no hard binding, you can use blade].

The customer wants the content manager to be able to create pages himself, i.e. want to embed into an already working CMS site.
They use the LaravelNova admin panel, but again, they want to create the pages themselves.

Who has experience in this, please tell me convenient CMS on Laravel. And is it possible to build them into a finished project?

PS So far I've googled OctoberCMS, but it's not clear whether it will fit an already launched project or not.
Rewriting from 0 is not an option - the site is rather big.