Block access to Wp-Admin and Wp-login.php from Non-Admins

I want to Block access to Wp-Admin and Wp-login.php Pages from Non-Admins.

Now, I don’t want to use any plugin for this.

Is there any PHP code snippet in which, even if people deliberately type “mydomain.com/wp-admin” or they deliberately type “mydomain.com/wp-login.php” , it will still redirect them to the Login or Register Page I’ve created, and will prevent them from ever seeing the Wp- Admin Page or Wp-login.php Page?

Any Code Snippet like that?

Regards.