In chapter 15 of the administrators guide

https://docs.oracle.com/en/database/oracle/oracle-database/21/olsag/label-security-administrators-guide.pdf

the use of DataPump is covered. In a nutshell

- full database export/import should handle it for you (as long you as have the FULL priv which entitles you to see everything). The LBACSYS schema will be cloned over.
- schema/table level requires a few more prereqs, eg

EXECUTE privilege on the SA_POLICY_ADMIN package
FULL privilege to write the labels

and pre-creating labels before import, eg

set serveroutput on
BEGIN
 dbms_output.put_line('BEGIN');
 FOR l IN (SELECT label_tag, label
 FROM dba_sa_labels
 WHERE policy_name='HR'
 ORDER BY label_tag) LOOP
 dbms_output.put_line
 (' SA_LABEL_ADMIN.CREATE_LABEL(''HR'', ' ||
 l.label_tag || ', ''' || l.label || ''');');
 END LOOP;
 dbms_output.put_line ('END;');
 dbms_output.put_line ('/');
END;
/

but please check chapter 15 to get the complete set of requirements/tasks.