When you access a Notes database through a browser, you may be prompted for a username and password.
Login dialog when calling a URL
This depends, among other things (e.g. Web SSO), on the settings in the ACL of the database being opened. By passing the username and password in a URL, you can avoid the login dialog.
How passing the credentials in a URL works
Provided that an ‘Internet password’ has been set in your Person document in the server's NAMES.NSF, access should be possible after confirming the dialog mentioned above.
To save yourself from having to enter the username and password, you can pass both components in the URL. For example, any URL such as:
http://192.168.0.10/mail/usermailbox.nsf
can be passed in the form:
http://username:password@192.168.0.10/mail/usermailbox.nsf