Anh,
Converting your Oracle database from Standard to Enterprise is something your DBA will need to do for you.
We in DLP Support cannot do that for you.
Regarding your question about just importing the license, that will not work.
See the following Oracle support page for the steps to convert from Standard to Enterprise:
https://docs.oracle.com/en/database/oracle/oracle-database/19/upgrd/migrating-from-standard-to-enterprise--database.html
David Spoons
Broadcom DLP DSE