SQL & PL/SQL

I want to select date with time including milliseconds from edit_sysdate.

Query 1: is works fine.

select EDIT_SYSDATE,TO_CHAR(EDIT_SYSDATE,'DD-MON-RRRR HH24:MI:SS') EDIT_SYSDATE_Milisecond  from EMPLOYEE a WHERE  Employee_id = '0002';

Output:

EDIT_SYSDATE           EDIT_SYSDATE_MILISECOND     

-----------------                -----------------------------

28-DEC-19                   28-DEC-2019 18:35:01

My Query is: it is not working

select EDIT_SYSDATE,TO_CHAR(EDIT_SYSDATE,'DD-MON-RRRR HH24:MI:SSxFF3') EDIT_SYSDATE_Milisecond  from EMPLOYEE a WHERE  Employee_id = '0002';

My Expected Output is:

EDIT_SYSDATE           EDIT_SYSDATE_MILISECOND     

-----------------                -----------------------------

28-DEC-19                   28-DEC-2019 18:35:01:124

Please help.