How to redirect an App to the main page without Login page?

I build an App with the last version of shopify/cli and Remix.

The default code introduces a route auth.login, I don’t understand the use of this route ?
When my app is installed, if I click to the name of the app in the admin menu of my shop, I access https://admin.shopify.com/store/MY_STORE/apps/MY_APP, which shows a login Form :

How can I avoid this page ? I just want people to access my default app._index.tsx page, which shows my content.

I don’t understand, because if I change manually the URL to add for exemple: https://admin.shopify.com/store/MY_STORE/apps/MY_APP/app/dashboard, which one of my custom routes, it works.

But, https://admin.shopify.com/store/MY_STORE/apps/MY_APP/app show the same login form.

Can you explain me please ?

As far as I understand, in my route app._index.tsx, I have a redirection:

  if (user) {
    return redirect("/app/dashboard");
  }

If I remove the redirection, the app._index.tsx is well loaded. The URL of the redirection works, I can access it directly.

Why is this redirection causes this effect ?