issue with executing Oracle Datapump API for expdp and impdp

Hi Team,

As part of Automating oracle schema refresh, we planned to use the Datapump API for expdp and impdp the schema backup, but when we used the below mentioned scripts we are getting the error as mentioned below, we have tried multiple trouble shootings but still no luck ..

We are executing in 12C database server, can you please clarify, how to rectify this issue. 

Script used:

declare

 h1  number;    

  begin

      h1 := dbms_datapump.open (operation => 'EXPORT', job_mode => 'SCHEMA', job_name => 'EXPORTJOB', version => 'COMPATIBLE');

     dbms_datapump.set_parallel(handle => h1, degree => 1);

     dbms_datapump.add_file(handle => h1, filename => 'EXPDAT.dmp', directory => 'DATA_PUMP_DIR', filetype => 3);