He said “전에 다니던 회사, which means he is not a current employee anymore.
And, that was exactly the case for me (Vanguard 401k with previous employer -> Fidelity IRA , not 401k).
Vanguard was notified by the ex-company as soon as I left,
(most companies suggest their ex-employees to roll over a 401k account for convenience)
and they confirmed that I didn’t need to ask my previous company for anything.
I had two choices: pushing from Vanguard vs. pulling from Fidelity.
I selected the latter process because it was much easier and smoother.