Any app should have a public contents, and a hidden contents reserved to authenticated users. Else, be sure that your app will not work if it’s not an internal app.
The login form for public app is available in the menu, if you have the menu displayed (aka if you have at least one tab moved to the menu section). If your app is a pro app, build it using the email whitelist mode, so that you can manage user profiles, and admin users, to manage components visibility by “signed in user”.
When your app is ready for production, switch the authentication to “public”. Your admin users will be able to connect and see what they are entitled to see and use. And your visitors will be able to log in, manage their profile, retrieve their past orders and so on.
This is a trick, but it works. Not sure if it’s a long term trick but anyway, this is a must have for apps so I guess Glide team is working on this “hybrid” mode.