Use .env in vite config file

vite.config.js

import { fileURLToPath, URL } from "url";
import { defineConfig, loadEnv } from "vite";
import vue from "@vitejs/plugin-vue";

export default ({ mode }) => {
	process.env = Object.assign(process.env, loadEnv(mode, process.cwd(), ""));

	return defineConfig({
		plugins: [vue()],
		base: process.env.VITE_BASE_DIRECTORY, // can be used now
		resolve: {
			alias: {
				"@": fileURLToPath(new URL("./src", import.meta.url)),
			},
		},
	});
};