Environment variables

What's the intended method to access environment variables in Start in isomorphic code like createRouter?

(import.meta as any).env.VITE_MY_URL

(import.meta as any).env.VITE_MY_URL

works on the client and server and

import.meta.MY_URL

import.meta.MY_URL

and

process.env.VITE_MY_URL

process.env.VITE_MY_URL

don't.