Error when running a dbms_datapump procedure

Database version - 19.18

OS - RHEL 7.9

I created a custom script to copy schemas using dbms_datapump feature. I get the following error when trying to execute it.

--------------Error Msg start---------------

ERROR at line 1:

ORA-39001: invalid argument value

ORA-06512: at "SYS.DBMS_SYS_ERROR", line 79

ORA-06512: at "SYS.DBMS_DATAPUMP", line 4930

ORA-06512: at "SYS.DBMS_DATAPUMP", line 6881

ORA-06512: at line 10

ORA-06512: at line 18

----------Error Msg End-------------------

-----------Code start-------------------

DECLARE

PROCEDURE LOG(msg VARCHAR2) IS BEGIN dbms_output.put_line(msg); END;

PROCEDURE mrw_copy_schema(p_schema_from VARCHAR2,p_schema_to VARCHAR2)

IS

v_job_name VARCHAR2(30) := 'COPY_SCHEMA_1';