Looks fine to me. Except for jb_function, of course.

JB_FUNCTION is the function you're referencing in your prepared statement:

   my $func = $dbh->prepare(q{
     BEGIN
       :rv := jb_function( parameter1_in => :parameter1);
   END;
  });
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Whatever this is, you don't have one in your database. I don't have one in mine, either, so the error message looks pretty much as I'd expect.

To get a working, example, I'd try something simple, such as :rv:=length(:parameter1) and don't change anything else.

In production, you'll probably want to change this to call the LINES_EXTRACT function/procedure that you reference in the initial comments.