TDE related steps during PDB cloning with EBS R12.1.3

we have EBS R12.1.3 instance with 19.7 database.

We have recently upgraded our database from 12.1.0.2 to 19.7 with TDE successfully.

Now, during the cloning (from PROD to DEV), we are facing issue with TDE keys.

We are following the cloning document 2560690.1.

We are able to open the CDB database, but we need to change the PDB name as DEV instance name.

We are getting the below issue when trying to do that :

SQL> alter pluggable database <Source DB SID> unplug into '<target DB Oracle_home/<Source_SID_PDBDesc.xml>';

ERROR at line 1:

ORA-46680: master keys of the container database must be exported