How to Insert the Salesforce Users Using Salesforce Apex Data Loader
Following fields required when inserting new users Using Salesforce Apex Data Loader:
Email Encoding (EMAILENCODINGKEY)
Time Zone (TIMEZONESIDKEY)
ProfileId (not profile name but rather the 15-character ID from the URL of the profile in the UI).
Generate new password and notify user immediately:
This checkbox is not available in the Apex Data Loader and as such a password is not generated with created this way. So Instead, you are able to select the desired users from a User list view that you define and reset the password for all selected users from the view itself using the ‘Reset Password” button.