I need to attach an explanation to my tax return. Is there a supplementary form for this in TurboTax? I can't find one. I would like to file my return electronically.

I need to attach a statement to my tax return for a statement required for the tax return for a Master Limited Partnership.  I also have to delete the sale of the MLP from the brokerage statement and report the sale using the Turbo Tax input for the sale.  Can I attach a statement to my return?  Where do I find the form?  I want to file electronically.