How to use vite env variables and modes?

[isorna]

Hi, I'd like to get access to vite's ìmport.meta.env.MODE variables and other env variables available in vite, but there seems that whenever I try to access them from config/index.ts it's not possible, and app throws this warning:

▲ [WARNING] "import.meta" is not available with the "cjs" output format and will be empty [empty-import-meta]

    docs/.vitepress/config/index.ts:6:34:
      6 │ console.log(process.env.NODE_ENV, import.meta.env.MODE)
        ╵                                   ~~~~~~~~~~~

  You need to set the output format to "esm" for "import.meta" to work correctly.

I've been searching for some hints to help me solve this problem, but I've not found anything that really helps me. Any ideas?

Regards