importing Unsubscribes and Hard bounces
There are two ways you can import unsubscribes and hard bounces:
Using Is Unsubscribed Column mapped to Is Unsubscribed field
Before you import, add Is Unsubscribed column in your CSV file and set all values to 1 or TRUE or Yes.
Map the column to the isUnsubscribed field.
Import to a list (call it Unsubscribed Contacts, or whatever you prefer).
After import, go to the list and on the settings icon ⚙️, select Unsubscribe all Contacts in the List.