use NITRO 100% works

// nuxtconfig

export default {
    runtimeConfig: {
        public: {
          YOUR_VAR: 'hello',
    },
  }
}

/// cmd

yarn build

cross-env NITRO_PUBLIC_YOUR_VAR=bye node .output/server/index.mjs

// runtime

console.log(useRuntimeConifg().public.YOUR_VAR) // 'bye'