Admin only without /ghost path

I want to use Ghost admin and Next.js API only without Ghost Theme.

Currently I have the following setup:

I want to get Ghost admin at and disable Ghost Theme autogenerated index page. Then I’ll use the JS API to get my blog index at mysite/

Final wanted setup:

  • Blog index with NextJS=> mysite/blog
  • Ghost Admin => blog.ghost
  • Website with NextJS => mysite

Is it possible to do this ?