Refers to article to How to add/edit/delete User Role?
1. In creating user page, click on user role fields dropdown to get a list of available roles for a user.
2. Select your required role(for example, Test Engineer role) from the drop down list to add to the user.
3. Click on Create button to save user role along with user details.
4. Click on name in the table list. It will display the user details page.
5. To delete due date field go to edit user page, remove value for due date and click on update