Form 926 needs to be added to the list of forms TurboTax provides. I completed my 2018 tax return using all forms generated by TurboTax. However, Form 926 is not available on the product so I had to manually create that form by going to the IRS website. Because of this I am unable to file my return electronically. If I am not able to file electronically, there is less of a need to use TurboTax.
There are many IRS Forms not supported by TurboTax - https://ttlc.intuit.com/community/forms/help/which-irs-forms-are-not-included-in-turbotax/00/25551
There are also certain tax situations and calculations not covered by TurboTax - https://digitalasset.intuit.com/DOCUMENT/A7aTcVUwu/2018-unsupported-calcs-L1FQfTTgn-073019.pdf
IRS Form 926, Return by a U.S. Transferor of Property to a Foreign Corporation would not be an IRS Form that would be supported since it is applicable to very few taxpayers - https://www.irs.gov/pub/irs-pdf/f926.pdf
As stated in the Form 926 instructions -
When and How To File
Form 926 must be filed with the U.S. transferor's income tax return (or, if applicable, exempt organization
return) for the tax year that includes the date of the transfer.