The Bridge can import existing users from JIRA and create respective resources in MS Project. To start the import, do the following.
Select JIRA>Import Users in the main menu
The following window will appear.
Start typing in a search string. A list of the users matching the search string will be displayed.
You can also filter out all users from a user group, all users who have access to a selected project or all users mapped to resources in the current project.
To import or update resources for selected users, click Import.
import a particular user and assign him or her a particular task(s) in MS
Project, select the task(s),
perform steps 1-3, select a user from the list and click Assign.