TurboTax is not offering loans at this time. At the beginning of the 2019 tax filing season there were refund advance loans available for the first few weeks of the tax season, but you could not opt in--the loan had to be offered to you when you filed. We do not know if those loans will be offered for the 2020 season. If they do have the loans again it will not be until January.
Last year they offered refund advances to selected customers at the time of filing and only after the IRS accepted the filed tax return. That was in Feb and March but it must be offered - you cannot apply for it. It is not known at this time if that will be repeated this year.