when you say "rollover my 401K to IRA account" is the goal to convert it all to Roth?
generally you can rollover the 401K to IRA without any tax; conversion from the IRA to Roth is then taxable.
what is the make-up of your 401 is it entirely pre-tax contributions/earnings, or do you have after-tax contributions, or any sort of Roth 401k balance etc? If you have after-tax contributions in the 401K some plans/custodians allow that balance to be rolled over to Roth.
but if you are using your IRA for backdoor Roth conversions which relies on having zero balance/basis in the IRA to make the backdoor Roth conversion non-taxable, if you convert your 401K to IRA and then don't convert it to Roth and have a balance in the IRA then you won't get the same tax advantage on backdoor Roth conversions.
if you can explain a bit more about your situation and what you are looking to accomplish that may help
A backdoor Roth IRA is not an account, it is a process. You make a non-deductible contribution to a traditional IRA, then convert it to a Roth IRA.
This process does not work if you have any pre-tax money in any traditional IRA, because all IRA accounts are grouped together for the tax and rollover rules.
If you currently have no pre-tax money in a traditional IRA, and you rollover your pre-tax 401k into a traditional IRA, you will not be able to do any more backdoor Roth IRA conversions unless you convert all your pre-tax IRA to a Roth IRA and pay the required income tax.
Generally, a Rollover of 401k or similar plan to Traditional IRA severely compromises the tax-free aspect of Backdoor Roth contributions.