I want to display a banner only on a specific portal.

Dear Expert

Please help.

Our company's instance has multiple portals in the Employee Center.
Portals have access control for each associated employee.
Until now, banner announcements have been displayed on all portals.
To inform users, I would like to display an announcement banner only on a specific portal. Is this possible?
If so, please let me know how to set this up.

Thank you in advance.