Executing Shell (bash) from PL/SQL
You need to create an external job for that.

Techniques for External Jobs

First, you need to create a credential, with the OS user and password in whose name the job will run:

begin
  dbms_scheduler.create_credential
  (
    credential_name =&gt; 'my_credential',
    username        =&gt; 'oracle',
    password        =&gt; 'Oracle123'
  );
end;
/


After that you can use this credential when creating an external job. For example calling your convert script with 2 arguments (input and output file)

begin
  dbms_scheduler.create_job
  (
    job_name             =&gt; 'convert_job',
    job_type             =&gt; 'executable',
    number_of_arguments  =&gt; 2,
    job_action           =&gt; '/usr/bin/bash/convert.sh',
    auto_drop            =&gt; true,
    credential_name      =&gt; 'my_credential'
  );

  dbms_scheduler.set_job_argument_value('convert_job', 1, '/home/oracle/file.in');
  dbms_scheduler.set_job_argument_value('convert_job', 2, '/home/oracle/file.out');

  dbms_scheduler.enable('convert_job');
end;
/