How to add an attachment for Oklahoma 512S efile

[Killebrew3]

Oklahoma is now REQUIRING e-filing of 512S, the state equivalent of the federal 1120S. No problem there as far as I can see with TurboTax Business

BUT ---- They also require the inclusion of the approval letter granting Pass Through Election (PTE).

So, how can I comply?  Have to efile, and must include the letter - but I see no way to upload an attachment.

[RobertB4444]

You need to first register for an OKTAP account.  Here is where you do that.  You can theoretically submit all of your forms there.  Which is good because you absolutely can not attach a file to a state tax return filed through TurboTax.