So you are looking to only use one app that’s set to Public, but have a password protected section inside of it? You can do something like that if you look at this post. You would just have to create a new column in the data tab for your “admin” sheet that is set to ‘User Specific’. Then create an if then column that checks the entered value and sets true or false if the value matches. You can use the if then column to then set visibility on other components that are only accessible to the user that enters the correct password. Unfortunately you can’t allow the user to set their own password.
If you aren’t using a lot of rows and are using the free version of Glide, you can create a second admin app, but I’m not a big fan of using two apps for various reasons.
There is another method that I’m currently discussing with Glide that would be much better, but I want to wait and see what they say first.
Edit: forgot to post the link to the post I was referring to.