You must be a project admin in the project in order to perform the below actions.

1. Raise a request via Service Now, support will assign the users with JIRA access permission
2. Access to the project you wish to assign access permission to users
3. Select Project Settings > Users and roles > Add users to a role > Users or groups
   
   
4. Enter the users you would like to grant access in this specific project
   Can add multiple users in users or groups field
5. Under Role, choose the correct role to be assign to users

6. Role Reference:-

   Role	Description	Permissions
   Administrators	Project admin for the specific project	Full project permission
   Users	Standard users for the specific project	Browse Project, Create Tickets, Add Comment, Transit Ticket Status, Manage Sprints, Work on tickets in the project