Well the admin template you want to integrate has support for using Laravel as backend API. If you want to use it with Intertia it should be possible, but they don't offer any support for this. So if you get stuck with integrating inertia you can't ask their support for help.
Check this link https://demos.pixinvent.com/vuexy-vuejs-admin-template/documentation/faq/#laravel-and-inertiajs-support
If you need more info or have more questions, don't hesitate to reach out.