If I got your question right,
you want the user to try to login and if they can’t they need to enter user name or email to restart their password ?
If this is the case you need to enable anonymous users in your app and then trigger a restart password workflow with a parameter of a user name of email.
Thanks for the response Alex its very informative. I actually need to build the original log in function as I am unsure how to do this.
In the navigation of the module ‘Project [APP NAME]’ there is an option to create a page for the home page.
You can create a login option here by adding the login-id text box, password-id text box and a sign in button.
When you've done that, you can choose to which page the users go to based on their user roles (if that is needed).
Regarding your forgot password, you can use this helpful guide: https://docs.mendix.com/appstore/modules/forgot-password
Lastly, i would recommend downloading the module ‘Administration Module’. This gives some standard pages to manage your users.
Hope this helps!