If this was truly a 401(k) plan, the 401(k) plan was required to provide you with a Form 1099-R that you need to enter into TurboTax to report the direct rollover. Contact the plan administrator to obtain the form.
If the employer plan was instead a SEP-IRA plan or a SIMPLE IRA plan, a trustee-to-trustee transfer is not reportable and the IRA custodian would not provide you with a From 1099-R.
