Connected to Oracle Database 19c Standard Edition 2 Release 19.0.0.0.0 
Connected as system@//localhost/TEST

SQL> create table dropme_t(n number);

Table created


SQL> create table dropme_log(user_ varchar2(30), date_ date default sysdate);

Table created


SQL> 
SQL> create or replace trigger dropme_trg before insert or update or delete on dropme_t
  2    declare
  3        procedure log_ is
  4            pragma autonomous_transaction;
  5        begin
  6            insert into dropme_log(user_) values(user);
  7            commit;
  8        end;
  9    begin
 10        log_;
 11        raise_application_error(-20001, 'I''m lazy student');
 12   end;
 13  /

Trigger created


SQL> insert into dropme_t values('bI!');
insert into dropme_t values('bI!')

ORA-20001: I'm lazy student
ORA-06512: at "SYSTEM.DROPME_TRG", line 10
ORA-04088: error during execution of trigger 'SYSTEM.DROPME_TRG'

SQL> drop trigger dropme_trg;

Trigger dropped


SQL> 
SQL> create or replace trigger dropme_trg before insert or update or delete on dropme_t
  2    pragma autonomous_transaction;
  3  begin
  4    insert into dropme_log(user_) values(user);
  5    commit;
  6    raise_application_error(-20001, 'I''m lazy student');
  7  end;
  8  /
create or replace trigger dropme_trg before insert or update or delete on dropme_t
  pragma autonomous_transaction;
begin
  insert into dropme_log(user_) values(user);
  commit;
  raise_application_error(-20001, 'I''m lazy student');
end;

ORA-04079: invalid trigger specification

SQL>