Each page within the account app has its own template to display that page's content.
Where to save template files
Template files will go in a folder that has the same name as the app instance key. The account app is for public accounts and does not have multiple app instances. It's app key is "account" and the name of the template folder is also "account". You would put all of your template files within the account folder inside the templates folder.
If your theme was called "Custom" then this would be an example folder structure:
Account pages and their templates
Below is the list of account app pages and the name of the template file that you should create.
The app home page often shows the logged in account holder information and provides link to edit the account or log out.
Template name: home.twig
This page shows the app form for edit the account. Set up the "Edit Account" form under Users -> Public Accounts -> Forms.
Template name: edit.twig
This page shows the the login form. Set up the "Login" form under Users -> Public Accounts -> Forms.
Template name: login.twig
This page is used to display a message if the logged in user tries to access content that the have not been giving permission to access.
Template name: not-allowed.twig
This page shows the password reset form. It's used to reset the password for an account that is not logged in. Set up the "Password Reset" form under Users -> Public Accounts -> Forms
Template name: password-reset.twig
This page shows a form that allows someone to register for a new account. Set up the "Register" form under Users -> Public Accounts -> Forms
Template name: register.twig