You can manage users and permissions within Business Central. You need to assign permission sets to users based on their role as described below. You can learn more about assigning permission sets to users or user groups in the Microsoft Business Central documentation.
Permissions for all users
All users require the role NAV-X LIBRARY assigned. it will automatically done at the time of installation of the app, so all users that exist at this time will have this this role already assigned. However, any new users will require this role to be setup when the user is created.
Permissions for Search users
Any user who is involved in setting up the Search functionality or would like to use the Search functionality requires additional permissions configured. The permission set SEARCH will have to be assigned to those users. This assignment should be done before the Search setup is started.