JavaScript file missing when buildling

I have a vanilla JS application. I'm using Vite as a frontend build tool.

  <script src="./src/main.js"></script>
  <input type="button" value="Connect" onclick="connect();" />

The code above works locally, but when it builds, it does NOT produce JS file in the dist folder (which I set to deploy), and hence the program errors when deployed.

The error is Uncaught ReferenceError: connect is not defined at HTMLInputElement.onclick

How can I solve this? I deployed it to Firebase hosting using Vite to build.

Edit: I moved main branch to Svelte so it works, but vanilla js does not work, which is in the petite-vue branch. If you want to test it out for the error, please check out this branch.

The source code is here https://github.com/leochoo/emotion/blob/petite-vue/index.html