@Morimoto Kazuki:
What do you want to achieve? If you really want to use a custom login page you will need Anonymous access enabled for that custom login page. Anonymous users should not have any access to content that is locked behind a login.
Hello Morimoto,
You basically need to set your security settings to production(i advise to do this directly when starting a project).
Then you can add userrole to your application which you can connect to module roles.
https://docs.mendix.com/refguide/user-roles/
This also forces you to sign in when you try to access your application, normally you end up here(this is the basic sign in page):
But you can create your own sign in page there are multiple ways to achieve this, search the forum there are plenty of answers :
here a link to a blog of enabling security and creating sign in page:
https://www.mendix.com/blog/enabling-security-and-adding-a-login-page/
hope this helps,
Good luck!