Trigger adds a value with sequence CAN`T solve

Question

I`m trying to solve a trigger issue. So I have to replace the value for every inserted row with new value from the sequence DEPARTMENTS_SEQ. And I ended up here

create or replace TRIGGER hr_insert_tr on DEPARTMENTS
    BEFORE INSERT on DEPARTMENTS 
    for each ROW 

BEGIN
    DEPARTMENT_ID = :new.DEPARTMENTS_SEQ;
END;

Answer 1

That would be

create or replace trigger hr_insert_tr
  before insert on departments
  for each row
begin
  :new.department_id := departments_seq.nextval;
end;
/